The boss of the first level is pretty ♥♥♥♥♥♥♥ strong when you are playing alone but he is beatable.
Make sure to play with at least 1 bot and spam kick when he grabs you.
And that's all for beating the first boss because the only reason the boss is so strong is that when you play alone he wil beat the ♥♥♥♥ out. One of the biggest reasons the boss from the 1st level is because he will never fall on the ground.

Here is a very good guide I found from an user you should check out and leave a nice comment on his guide http://gtm.you1.cn/sharedfiles/filedetails/?id=759942832

DISCLAIMER: For the good ending you have to take no Nekro while fighting against the boss.
Step: 1. Yeah uhm if you play the last level of the game just turn the difficulty of the level to easy (even doh I told you in the beginning of this guide not to) and invite 3 friends to your house.
Step: 2. Done ? ok good. oh yeah and they should bring some controllers because bots are useless.
Step: 3. Play the last level normaly. The fight against that old ♥♥♥♥♥♥ can get hard if you don't knock him off the ladders. You don't have to kill the mobsters, police men or however you wanna call em you just have to kick that dude from the ladder and kill that dog because he is pretty ♥♥♥♥♥♥♥ anoying.
Step: 4. Fight against Nekro.
Step: 5. Fail.
Step: 6. Read this guide.
Step: 7. I actually havn't beaten Nekro yet but I will tell you what to do.
Step: 8. In the first part of the battle you just have to throw the needles at the wall and try not to run against the wall or get stabbed otherwise you can just ♥♥♥♥♥♥♥ load the last checkpoint because you will need the health in the third part of the battle.
Step: 9. Ok wave 2 you have to kill the flying blood fists from the air but watchout they have broken hitboxes so try attacking the lowest part of the fist. Other then that You should watch out not to get crushed by the fists. If the spiders bite you it isn't that bad because you can slide or jump to get the away from you I don't ♥♥♥♥♥♥♥ know.
Step: 10. Fight against Nekro.
Step: 11. listen to this ↓ https://www.youtube.com/watch?v=vfblUSCaAQk
Step: 12. JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP JUMP
Step: 13. ???
Step: 14. Profit

And here is a picture of a goose.
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