Hey everyone, if you're having trouble with Moskito (the first boss), here's an easy way to defeat him.
First, when you get the chance, punch him and he'll go a bit dazed for a few seconds. When he snaps out of it, before he flies to the top of the screen, punch him again, and continue this till he dies. You can use this for both Moskito fights.
Note: You can't use this hint for the playstation version of the game, I've tried.