[FREE] [GAME] [ARCADE] Bug Attack

Please, give me some advices about this game - which improvement should be implemented? This is my first experience in game dev without direct tutorials. The goal of the gane is simple - touch on the screen for destroying the bugs. There are different types of bugs: some one needs two or three touches. There is Power Up button in upper-left corner you. This Power Ups different for each game World (Big Thumb, Freeze, Explosion). There is also Endless (Survival) game mod.
Link to game: https://play.google.com/store/apps/details?id=com.coolstuff.bugattack

Graphics was made in vector.

Engine - AndEngine.

UPD
Rate exchande in 24 hours ))

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