I would put this as a neutral review if I could. The core gameplay with the cars and races themselves is incredibly fun ; absolutely no complaints there. The open world touch helps tie everything together as well -- I used to explain that Just Cause 2 was my favorite "Get from Point A to Point B Simulator" because the best part of the game was setting a random waypoint on the map, spawning in whatever vehicle tickled your fancy at the time (there were some good mods that let you airdrop vehicles in JC2 like the devs worked into the official JC3 game). Forza Horizon 4 scratches the same "Get From Point A to Point B" itch (cars only), but adds a lot of other fun unlockables on top of everything else.

So why the 'neutral' review? Because outside of the core gameplay with cars / races, it feels like literally everything else was an afterthought. Will try summarizing the things that legitimately just made me angry while playing the game:
(1.) I use a wired connection to my router and get ≈300Mbps download and ≈ 260Mbps upload. That should be more than okay to play the game, but still constantly get stuttering and see cars pause in place and then slingshot forward while playing online. Assuming most of this is done serverside, so my own internet speeds may not factor in admittedly.
(2.) The main menu / GUI is the most atrociously-designed / horribly-laid-out menu I've ever used in a video game. And there's no way around needing to use it all the time. Even at around the 10Hr playtime mark, I still sometimes had to flail around in the menu before I found the area that had what I was searching for.
(3.) There are far too many unskippable cutscenes in between events and when areas of the overworld map are being unlocked. If you don't have certain DLC, the game occasionally plays advertisements in the middle of the game that you purchased for said DLC. Never should a non-free-to-play game EVER advertise in the middle of its game.
(4.) The Super-7 'challenge editor' -- which is the track editor that players can use to create custom objectives and then upload for other players to attempt -- is a fantastic concept that is completely ruined by its horrible implementation. Like I wasn't even planning on creating a bunch of challenges, but I wanted to try it at least once. From that experience, I can guarantee I will never use it again. What I've found out:
...(4a.) Your challenge is 'locked into' using whatever car you were driving when you opened the 'Super 7' menu. After you're done creating your challenge, there is no way to designate the car from your garage that you want other challengers to use if they come across your upload.
...(4b.) Similarly, the 'starting point' of the challenge is locked into the exact location your vehicle was at when you opened the 'Super 7' menu. There is no way to move the starting point after you've started making your challenge.
...(4c.) You set the 'ending point' of the challenge by selecting a point on the FH4 map GUI, BUT the ending point 100% HAS TO BE on a paved road or a dirt road. This means you can't create custom off-road challenges, which is astounding to me because a huge part of the game are the "Cross-Country" races which are exactly that -- across the open country NOT on paved roads or dirt roads.
...(4d.) When you 'pindrop' the cursor on the map to choose the ending point of the challenge, the game just sort of guesses what you were aiming for. And if you're picking up on a theme here, it is impossible to change the 'ending location' of the challenge after it's placed.
...(4e.) 'Waypoints' -- another huge feature of the game (to force players to stay on an intended route) -- CAN'T be set for these custom challenges. So the devs clearly understood why these are useful in the core game, but didn't think that they would be useful for the custom challenges? It's baffling.
...(4f.) There is literally no 'Save' feature for your custom challenges. You have to suffer through the horrible editor all in one sitting (good luck), and nothing from your custom challenge will save from that sitting unless you upload the challenge at the end.
...(4g.) And I don't even think I need to say it at this point, but: no, you can't edit a challenge after you've uploaded it ; nor can you load an existing challenge as the starting point of a newly-created challenge ; you start from scratch every time.
(5.) Online Adventure: This is the unranked online group play (PvP). I dunno if Microsoft / Xbox Game Studios just gave up on their servers or something, but I have yet to finish one of these because the loading times at the start of every successive race are (without exaggeration) somewhere between 15-20min. And you have to do, at minimum, (3x) races to finish one adventure.
...(5a.) I bought this with my cousins to play multiplayer co-op in a small group, so I wouldn't normally care about Online Adventure, but the weekly 'challenges' / 'quests' (whatever you want to call them) apparently force you play Ranked Adventure, which you can only play if you get to 'Level 3' on the Online (Unranked) Adventure.
...(5b.) There are car rewards that are locked behind getting to a certain percentage-completion of the Weekly 'challenges' / 'quests', so when you factor in everything above, it's a pretty frustrating situation.
...(5c.) Just Google search "forza horizon 4 online adventure load times" for a sense of what I'm describing.
(6.) When searching through the list of your auctions placed in the Auction House, there's no way to reorder the list (where sorting by 'time ending soonest' would be ideal...). Instead the game locks your list of auctions in chronological order of when you placed the bids without an option to re-order.
(7.) For online play, you can't selectively mute the players that are in your session, so you'll often get stuck with someone with a hot mic blasting obnoxious music in the background and you can't mute them specifically. Another option that is very obviously needed and should have been straightforward to implement, but completely missed by Playground.
(8.) On the topic of muting sounds, there is no "mute" option for the in-game music (which isn't amazing...). The game settings have a "music" volume slider that goes from "1" (lowest) to "10" (highest). Like why is there not a "Volume 0" option for the music? Why is the lowest music volume setting "1" and not "0"? Also, the music volume slidebar is ONLY tied to the radio station music that plays while driving ; it does NOT mute the obnoxious music that plays during loading screens.
...(8a.) Again, there are no options to mute (or even turn down) the music during loading screens. At least for the radio station music, you can change the station to "OFF", but the game doesn't save your Radio Station preference to "OFF", so every time you get into a new car, you have to cycle through stations before you get back to "OFF" again. It's like the devs/publisher wanted to force you to listen to the music just because they had to pay licensing fees to get it in the game, regardless of whether you enjoy it or not.

Verdict: Forza Horizon 4 is a fun game, and I will probably continue to play it. I think it could have been a 10/10 game if the entire development time wasn't spent solely on the cars. Everything in the game BUT the cars feels like a complete afterthought the team slapped onto the game just so that they could market FH4 as having 'all of these exciting new features that previous Forza titles didn't have', as a marketing campaign that looks goods on paper. This game is simultaneously both fun and painful. I think all of the negatives take it down to a 6/10, hence the 'neutral' review that I wish Steam would have let me give it.

I would put this as a neutral review if I could. The core gameplay with the cars and races themselves is incredibly fun ; absolutely no complaints there. The open world touch helps tie everything together as well -- I used to explain that Just Cause 2 was my favorite "Get from Point A to Point B Simulator" because the best part of the game was setting a random waypoint on the map, spawning in whatever vehicle tickled your fancy at the time (there were some good mods that let you airdrop vehicles in JC2 like the devs worked into the official JC3 game). Forza Horizon 4 scratches the same "Get From Point A to Point B" itch (cars only), but adds a lot of other fun unlockables on top of everything else. So why the 'neutral' review? Because outside of the core gameplay with cars / races, it feels like literally everything else was an afterthought. Will try summarizing the things that legitimately just made me angry while playing the game: (1.) I use a wired connection to my router and get ≈300Mbps download and ≈ 260Mbps upload. That should be more than okay to play the game, but still constantly get stuttering and see cars pause in place and then slingshot forward while playing online. Assuming most of this is done serverside, so my own internet speeds may not factor in admittedly. (2.) The main menu / GUI is the most atrociously-designed / horribly-laid-out menu I've ever used in a video game. And there's no way around needing to use it all the time. Even at around the 10Hr playtime mark, I still sometimes had to flail around in the menu before I found the area that had what I was searching for. (3.) There are far too many unskippable cutscenes in between events and when areas of the overworld map are being unlocked. If you don't have certain DLC, the game occasionally plays advertisements in the middle of the game that you purchased for said DLC. Never should a non-free-to-play game EVER advertise in the middle of its game. (4.) The Super-7 'challenge editor' -- which is the track editor that players can use to create custom objectives and then upload for other players to attempt -- is a fantastic concept that is completely ruined by its horrible implementation. Like I wasn't even planning on creating a bunch of challenges, but I wanted to try it at least once. From that experience, I can guarantee I will never use it again. What I've found out: ...(4a.) Your challenge is 'locked into' using whatever car you were driving when you opened the 'Super 7' menu. After you're done creating your challenge, there is no way to designate the car from your garage that you want other challengers to use if they come across your upload. ...(4b.) Similarly, the 'starting point' of the challenge is locked into the exact location your vehicle was at when you opened the 'Super 7' menu. There is no way to move the starting point after you've started making your challenge. ...(4c.) You set the 'ending point' of the challenge by selecting a point on the FH4 map GUI, BUT the ending point 100% HAS TO BE on a paved road or a dirt road. This means you can't create custom off-road challenges, which is astounding to me because a huge part of the game are the "Cross-Country" races which are exactly that -- across the open country NOT on paved roads or dirt roads. ...(4d.) When you 'pindrop' the cursor on the map to choose the ending point of the challenge, the game just sort of guesses what you were aiming for. And if you're picking up on a theme here, it is impossible to change the 'ending location' of the challenge after it's placed. ...(4e.) 'Waypoints' -- another huge feature of the game (to force players to stay on an intended route) -- CAN'T be set for these custom challenges. So the devs clearly understood why these are useful in the core game, but didn't think that they would be useful for the custom challenges? It's baffling. ...(4f.) There is literally no 'Save' feature for your custom challenges. You have to suffer through the horrible editor all in one sitting (good luck), and nothing from your custom challenge will save from that sitting unless you upload the challenge at the end. ...(4g.) And I don't even think I need to say it at this point, but: no, you can't edit a challenge after you've uploaded it ; nor can you load an existing challenge as the starting point of a newly-created challenge ; you start from scratch every time. (5.) Online Adventure: This is the unranked online group play (PvP). I dunno if Microsoft / Xbox Game Studios just gave up on their servers or something, but I have yet to finish one of these because the loading times at the start of every successive race are (without exaggeration) somewhere between 15-20min. And you have to do, at minimum, (3x) races to finish one adventure. ...(5a.) I bought this with my cousins to play multiplayer co-op in a small group, so I wouldn't normally care about Online Adventure, but the weekly 'challenges' / 'quests' (whatever you want to call them) apparently force you play Ranked Adventure, which you can only play if you get to 'Level 3' on the Online (Unranked) Adventure. ...(5b.) There are car rewards that are locked behind getting to a certain percentage-completion of the Weekly 'challenges' / 'quests', so when you factor in everything above, it's a pretty frustrating situation. ...(5c.) Just Google search "forza horizon 4 online adventure load times" for a sense of what I'm describing. (6.) When searching through the list of your auctions placed in the Auction House, there's no way to reorder the list (where sorting by 'time ending soonest' would be ideal...). Instead the game locks your list of auctions in chronological order of when you placed the bids without an option to re-order. (7.) For online play, you can't selectively mute the players that are in your session, so you'll often get stuck with someone with a hot mic blasting obnoxious music in the background and you can't mute them specifically. Another option that is very obviously needed and should have been straightforward to implement, but completely missed by Playground. (8.) On the topic of muting sounds, there is no "mute" option for the in-game music (which isn't amazing...). The game settings have a "music" volume slider that goes from "1" (lowest) to "10" (highest). Like why is there not a "Volume 0" option for the music? Why is the lowest music volume setting "1" and not "0"? Also, the music volume slidebar is ONLY tied to the radio station music that plays while driving ; it does NOT mute the obnoxious music that plays during loading screens. ...(8a.) Again, there are no options to mute (or even turn down) the music during loading screens. At least for the radio station music, you can change the station to "OFF", but the game doesn't save your Radio Station preference to "OFF", so every time you get into a new car, you have to cycle through stations before you get back to "OFF" again. It's like the devs/publisher wanted to force you to listen to the music just because they had to pay licensing fees to get it in the game, regardless of whether you enjoy it or not. Verdict: Forza Horizon 4 is a fun game, and I will probably continue to play it. I think it could have been a 10/10 game if the entire development time wasn't spent solely on the cars. Everything in the game BUT the cars feels like a complete afterthought the team slapped onto the game just so that they could market FH4 as having 'all of these exciting new features that previous Forza titles didn't have', as a marketing campaign that looks goods on paper. This game is simultaneously both fun and painful. I think all of the negatives take it down to a 6/10, hence the 'neutral' review that I wish Steam would have let me give it.