I've played a few really great indie games recently and would like to share a bit about them. None of these games are brand-new and all are available in both Mac and PC versions.
Aquaria is a gem of a game for those that loved the original metriod games. In Aquaria you play a young mermaid creature that decides to explore her world beyond her home waters. In doing that you guide her through many adventures that reveal a bit about her world. The game is visually beautiful and the game mechanics, though simple, are very nice. You can play the whole game with a mouse if you wish though gamepads are supported too. In the game you access special abilities by singing different songs. It is a neat concept.
The game was made by an indie outfit of mainly two people out of Canada. But it feels much more than that. It's very big like an underwater version of Castlevania: Symphony of the Night, with multiple treasures to collect and many secrets to uncover. It is available for Mac, PC and Linux and it's also on steam.
Braid is an art piece. If you have heard of the games as art debate you have heard about Braid (and Shadow of the Colossus). In Braid it is the playing of the game that is treated like art. The game looks like a Super Mario Bros. clone, where you run around and jump on weird face and feet creatures that resemble goombas and jump platforms, that is until you die and suddenly you can reverse time and all actions back to the beginning. The game is a puzzle game but with the third dimension of time as a important game mechanic necessary for solving the puzzles. The backgrounds in this game are like moving paintings that reflect the direction of time and move forwards or backwards along with the enchanting music. The story will leave you puzzled too as it's very hard to make sense of it, but it does pose a very interesting question about "rescuing" princesses. Is that what you're doing?
Braid is available on Mac and PC under Steam.