This is super fun! I don't know what you've taken before making this game but this is very creative and funny. The game is simple enough to understand but extremely hard to master. I end up using the keyboard as it feels much easier than a controller. The game is super polished and smooth too, which these types of games really need. I also like that sound very much, it just fits extremely well with the game.
Not really much to criticise as the game was very well made, but I think there can be a bit more variations on how many inputs each vehicle needs. It would be nice to see super long inputs during the late game, which would make the game more challenging and fun. I would also suggest adding a bit more buttons later on. Just 8 right now would be way too comfortable if you are used to the inputs. Maybe combine inputs like 1 and right together as a single input or whatever.
Anyway, this is a very well-made and fun game! I like it a lot! Well done!
P.S. Here's my score with a perfect combo. How the heck are you getting 5k XD