For today only this very popular Apple Appstore game is free.
For those wondering this appears to be part of a program, as the app page says “Download The FreeAppADay Store App And Wish For A Top Rated Paid App Like “Death Worm” To Become Free For A Day!” so if you’re waiting on a game to be free, this might be worth your time to look into. As far as Death Worm its a cute little indie game with enough to do to warrant the time to download. It has quite a many good reviews and is listed highly on many sites.