Damn! Where to start? It's cool when a game makes you ask questions. My question was "was the banana a good choice". Other than that- awesome game. Really smooth gameplay, that you instantly "get". Simple graphics, but you made them work with those delicious post processing effects. Retro sound effects and music, really bring this home.
And the main thing. At the time of writing this post- this game has the best implementation of the theme. By far.
The only thing I would think to improve is the difficulty curve. Once you get all the powerups, you just tear through the enemy waves. It would be cool if the game went really hardcore then. Like "oh I see you got everything, now we get serious".
Keep up the awesome work!