Bought a couple games last week in "The Humble Indie Bundle". One of said titles was Aquaria, which is a lovely little game, definitely worth more than what I paid for it. It's a little hard to describe, but it definitely reminds me of Zelda and Iji. Lots of exploration, with a little bit of combat thrown in.
There's a demo available from the developer's site
here. You can even transfer your progress from the demo if you buy the full game. It's available both from the devs' website and from Steam, but honestly, there's no real point to buying from Steam unless you absolutely
must have achievements.