Seriously I've had countless amounts of occasions in Halo were it became impossible to play. Something like ODST, the checkpoints in that game were perfect. Wether it was after I killed a group of covenant or when I just found a supply cache the checkpoints couldn't have been better. Edit: For checkpoint problems they should make some sort of system that if you die over 7 or some random number amount of times immediately after a checkpoint, it asks you if you want to restart to the previous checkpoint.