I like the game, but it reminds me a lot of Super Crate Box by Vlambeer.
What is the "Only One"-ness of the game?
While i was working on it, Super Crate Box slowly crept more and more forward in my head. At first the map design was a different but after some playtesting it was a bit awkward and it went more and more in the direction of Super Crate Box. The Only one-ness is in the shared pool of powerups, there is only one pool that affects every creature in the game.