I am a veteran of this game and I will try to give the most neutral review of the game while being very experienced.

Geometry Dash is definitely an interesting game. It is a difficult sidescrolling platformer where music guides you. The game is hard to get into I will not deny that, it isn't for everyone. This game also has a surprisingly very active community, and tens of thousands of star rated custom levels. I will not deny that the community does have some toxicity, but if you know where to hang, you'll be ok. There are also many ways to enjoy the game. You can either create levels, try to beat very difficult levels, grind more easier levels, and way more. While the last major update took 7 years to get released, the creator of the game still regularly gives star rating to user levels to this very day and is involved with the community.

Positives:
-Practically infinite replayablilty
-Active community
-Complex level editor for all kinds of players
-Partial custom music support
-Plentiful of user made levels
-Multiple ways to enjoy the game

Negatives:
-Somewhat buggy
-Somewhat toxic community