I think this game is alright, but it starts to get repetitive and boring very quickly.
I really think that the levels could have been much more interesting if the levels had their own gimmicks and mechanics.
Edit: I just learned about Proto World and replayed the game to experience it... And I actually liked it. It's pretty alright, but it's A LOT better than the levels outside Proto World.
I really like the metriodvania gameplay, and I liked the boss fight, even if it was short. Proto World's art style reminds me of Count Bleck's castle from Super Paper Mario, and I really like it.
Proto World felt like it had more effort put into it than the main world.
I think this game is alright, but I really wish that more effort was put into the main world. I really feel that the levels could of really been really fun.