Hello, just thought I'd start a thread to recommend this game (since I couldn't find any other threads with the search feature). It's an indie game made by pretty much just one guy over a two year period, and it's incredibly good especially considering the fact that he decided to release it for free (I would probably have paid about 15$ for it, possibly even more. The first thing I did when I completed it was to buy the soundtrack!).

It plays very much like an old-school platformer where there's no hand-holding, and no stupid popups telling you how to beat the game. It's not unforgiving, but it's enough to feel satisfied when you beat a boss or get through a tough area.
It's very much an "open world" as well, as in, you can pretty much chose whatever order you want to do the areas in. There are some areas you can't access before you find an upgrade, but other than that there's nothing stopping you from collecting the treasures in whatever order you want. Also, the soundtrack is, in my opinion, amazing. I love the music in the game.

The only negative thing I can think of is that there are a few technical issues. It crashed every once in a while for me, but save stations appear fairly often so if you just remember to save when you see them it's not a big problem. Some people have trouble getting it to run, but most people seem to get it fixed by running it as admin or in compatibility mode. And then there's a few bugs here and there, but nothing game-breaking.

So if you're interested, try it out at:
http://www.robitstudios.com/treasure-adventure-game/