With Exoddus, you can "quicksave" your progress at any time, which is quite useful since both of Abe's games require a lot of precision and repeated deaths trying to figure out how to save all of the Mudokens. However, Abe's Oddysee has nothing of the sort, which can frustrate a new gamer after they just spent the past hour getting through a tough area, only to suddenly die, and find themselves back at a checkpoint, with none of the rescues having counted.
There is a sort of workaround for this. As you move Abe about, you'll notice little diamonds the pop up above him periodically. These are the checkpoints you return to when you die. Any progress you've made when you hit a new checkpoint is remembered (Muds rescued, Muds killed, Sligs killed, mines detonated, drones exploded, grenade/rock in hand). If you Save a game, through the menu, that last checkpoint is the one it'll save, regardless of where you are standing at the moment.
The "psuedo-quicksave" comes in if you backtrack to earlier checkpoints after accomplishing something, such as rescuing some Muds in a tricky spot, or finally having cleared a rough secret area. It's not as good as having a real Quicksave as the second game does, but it does save a lot of time if you can get your progress remembered before dealing with the next precision-based puzzle area.

yeah if it wasn't for this "feauture" I would have probably given up on the game altogether. Very useful indeed