You know when you die in a level and you get kicked back to the start? Thats what it's like to have no checkpoints. I hate it when I play through several minutes of a really boring part, then die and have to do those several minutes of a really boring part all over again. A big offender is the original Perfect Dark and Perfect Dark Zero on Dark Difficulty. After playing through the second level very cautiously, I was killed by the autoguns at the very end. Then I had to do the whole thing over again. A game with plentiful checkpoints, preferably one after every battle, is a good game.
I look snazzy in that Carrington Institute Shirt. Maybe I should make that Parker's outfit.