Autosave

So far the game saves when you move between levels or go past a checkpoints, which are roughly where the old savepoints were, minus the few that where close to doorways.
The little magnitude disk image comes up in the bottom right corner when saving, which will last 2 seconds after the game has finished saving, for visibility purposes.
A screen explaining the autosave icon appears between the game and the flyin, and can be skipped.

Thoughts so far?