I disagree. Although I agree that Bolly is definitely a very difficult boss, especialy the first time I played him, I soon found out it's easy to uppercut his long ball-and-chain thingy. After that's gone all you have to do is just wait for him to place his target on you and start stomping on him numerous times until he's done pwning the walls with his missles and starts moving around again. Then repeat it again and again.

Bilsy on the other hand is THE ultimate boss, in my opinion. He has a weakness, sure, when you stomp, you're immune to the fireballs he throws at you. I still find him more difficult than bolly, it's probably his ability to teleport that gets me at times.