Blaster Master came complete with what might be the worst storyline in the history of the NES, with the exception of certain RPGs. This is the way Sunsoft gave it:

Your average American teenager, Jason, was attending to his pet frog, Fred, who he kept in a fish bowl, when all of a sudden, Fred hopped out and away.

Stupid mistake #1: Keeping a frog in a fish bowl... of course it's gonna leap out, you dumb ass!

As Jason pursues his best friend Fred, the frog lands on a barrel of radioactive material that is sticking out of the ground. Fred then swells to about triple or quadruple his normal amphibian size, and falls into a pit. Jason, of course, dives in after him.

Stupid mistake #2: Jumping into a pit when you can't ascertain it's depth isn't exactly the wisest thing one can do. At least run home and grab some rope, boy.

Miraculously, Jason lands unharmed. As he looks around, he sees a huge tank standing in front of him. Jason grabs the radiation suit (which amazingly fits) from inside the tank (which, by coincidence, still has the keys in it). And he goes on a quest to save Fred.

Stupid mistake #3: Climbing inside a mysterious tank with (I'm assuming) no prior experience in mechanical warfare, and driving it into a mysterious cavern with giant mutants in it!

There is another way to look at this, though... consider Jason a rebellious lad with a penchant for illegal substances

Jason had just finished taking a huge acid hit when a mysterious frog appeared inside Jason's over-sized bong and began to speak to Jason about his wild soul rampaging in the wilderness of underwater cheese oppressors. In the middle of the conversation, the strange frog hopped out of the bong and into the back yard. Jason pursued, hoping to learn more from his amphibious visitor. ''wait up, little green dude!'' Jason called

The strange frog hopped into an odd container which had just popped out of the ground. In front of Jason's eyes, the frog began to glow and then expanded to triple it's previous size. ''whoa, man...'' observed Jason. The frog then fell into a hole, and Jason pursued, falling into the hole as well.

When Jason came to, there was a huge metal vehicle in front of him, and a gnarly suit inside. Jason put the suit on and decided to chase after the wise frog. Using the tank, Jason drove into a field full of mutants.