Blaster Master can be kind of a tough game. You have to take your little guy up against great big monsters that are way more nimble and way stronger than you are. But you have a secret weapon at your disposal: the Pause Button.

Make your way to the boss of area 2, 4, 6, or 7 (one of the frogs or one of the crabby things) and start chucking grenades at it. A successful hit will make it flash. Then, while it's taking damage, pause the game.

While the game's paused, the boss monster will continually take damage. Leave the game paused for about 30 seconds or so and you win! Pretty awesome!

Just be aware that this works both ways. If you're getting hurt when you pause the game, you'll keep taking damage until you unpause. And then you'll have to do the whole battle over again.