Nice work! Played the game all the way through, and overall really enjoyed it! The last level was challenging, but managable. Liked the differences between the bosses, and it is easy to see how this could be expanded in several interesting ways.
If you are to continue developing the game, I personally think it would be a bit more satisfying if, instead of the number of bombs increasing as much with time, the added complexity instead are given to the bosses. That could for example be in the form of more frequent jumps, or shorter weakness period for the two bosses respectivelly. With too many bombs you sometimes run into a situation where it almost feels impossible to make it out.