I found alot of good things here you had some good effort i think the main thing i really liked about this was the design and concept idea, But to be tottally honest with you it was entertaining, aswell as fun and exciting, so there was some rather good things about this, and it was sort of unique in its own way. This game is kind of interesting, i was not too fond of the whole interface and having to click on a button to restart you should make it so that if you can just click on spacebar or something to restart the game or stage, the music was pretty good, it was just right if you ask me, a fun game with some decent acheivments to gain, so a good game you have some interface changes would be nice. I cant help but wonder what else you have in store for us, You bring alot of quality to these kinds of games, so cant wait to see what else you have in store for us.
~~THINGS TO IMPROVE ON~~
This kind of game is fun but not always the easiest to suggest some ideas for as its already good, I may have found a few things that i could throw your way for some improvments, but here you go and hope they help. make it so that if you can just click on spacebar or something to restart the game or stage, instead of havving to drag mouse and click on retry, also more upgrades would be a big plus on this one.