Very awesome game! The idea of pigeons being the ones who can make you fail is hilarious - initially it wasn't obvious, but then... They kill you! Nice pixel art, nice music and overall fun.
To the sequel it would be good if there was none or less leaps of faith. There are some jumps that if you don't know the level beforehand you have a lot of probability to fail.
Also the final boss is cool, however if his bullets had some kind of telegraph - a sound, for example - it would help pass over him after a tough level (however I liked it and completed twice just for fun).