I used savestates when I was going for 100% completion of Crash Bandicoot. You need to get all the boxes in a level - if you die and respawn at a checkpoint, you lose all previous boxes opened. Not dying ever is not that difficult (I managed the majority of the game), but I savestated at every checkpoint I came across just in case I died. There is nothing more frustrating than dying with the end of the level in sight and knowing that you're not gonna get the 100% level completion because your timing was very slightly off. ._.