Take all the knuckle-mashing boss fights of the NES days and stick them together with Krazy-Glue and you now have Banana Nababa.
Banana Nababa has it all: Good boss design... Actually, that's all it has. Bosses, bosses, and more bosses. This game is literally all boss fights. Specifically the sort of boss fight from the NES era; long, grueling, and most of the time annoying.
That is not to say that this game is not fun. The bosses are made to be able to be defeated provided you can figure out their pattern of attack. Because of the difficulty, though, there is always a great feeling of accomplishment after you annihilate a boss.
Banana Nababa is a fun experience albeit a very difficult one.