Average
Colors and graphics are good. Would they be less chaotic and maybe smaller in a bigger playground then I would consider them to be even great.
Explosions should NOT be as prominent as living enemies - its confusing and chaotic!
Chaotic is actually the biggest problem of your game!
Very chaotic and too fast gameplay- at least at the beginning. A game should give the player the required time to learn how to play and to adjust to the controls and graphics.
Also the " how to play" button is by far too small (why the hell is it smaller than the other writing? ).
Slow it down, make it a little bit less chaotic and stuffed with animation and you you'll get a good- very good game.
Overall 6/10