Rather than going back to the checkpoint, you could also make it so the game uses a global.hp value, granting the player mercy invincibility when they come in contact with a hazard, of course. You could also give the players torpedoes with the same set-up (global.ammo) and make it so they either find them or regenerate them over time, whichever one sounds better.

You could also make it so colliding with a checkpoint saves vital information to an ini file (like your hp, your x/y positions, and how much stuff you have) so you can continue from where you left off. You don't really have to worry about that until the game gets bigger.

Of course, some of these things might have already been done, I'm just tossing out ideas.

Oh yeah, before I forget :p
Thanks