I'm gonna have to write this too in very near future.
If I am able to find a solution.. I'll add here... if you do .. don't forget to share :)
There are probably 2 kind of saves I need.
1. When player dies in a level and has to "Retry"... I'd prefer he plays from a certain checkpoint of the game.. IMHO cookies is best way here
2. When player quits the game and comes back .. he needs to see all his completed levels as DONE as well as be able to play the uncompleted stage from the checkpoint.
I'm sure saving some xml based info in a flat file would be easier than db (although, this is only for "installed" games) .. but I'm not yet sure how to access 'em via Scirra.
Need to think.