Everybody remember the movie The Core? Theia is like that. Something's gone wrong with the middle bit of the planet, and you have to get down there and sort it out.

But there's a catch. Of course there is. And that catch is that you have to walk. Fortunately, your character (who looks a bit like a sock monkey) does have some native advantages. She can tunnel under stuff, and she can push stuff.

Not exactly a blockbuster thrill-ride then. Fun though. The block-and-key puzzles put us in mind of the Legend of Zelda games.

Play Theia