Gameplay balancing.

[lendrick]

We've officially gone from Too Hard to Too Easy. :)

I think we should probably hold off on serious game balance until all of the gameplay things are implemented (inventory, experience, etc), but we definitely need to do this at some point. In the interim, I propose that we change check points into save points and eliminate the idea of lives entirely.

Once we've implemented an inventory system and some weapons and other powerups, we can start in on increasing the difficulty level a bit. For now, I want to have this task out there so we know it has to be done, but don't end up doing it over and over as we develop the game.