The game called Trine is another "indie" game that also deserves some attention. Also based on physics, it is a simple 2D platformer where you control one of three characters in the game. It also features the ability to let other people play along, making it a unique co-operative game. Having tried the demo, the gameplay is interesting enough to make me want to get it. However, like anyone would want these days, you'd look for a way to get the game as cheap as possible (that is, without resorting to getting a bootleg copy).
Recently, Braid was put on sale for US$5. Its regular price is about US$15. Braid is a unique game, as it is a puzzle platformer, focusing mostly on how to manipulate time. Yet it is much more complex than that. Often the solution is so obvious that it never occurred to you.
And then there's Fez, a 2D platformer set in a 3D world. Everything visually displayed is to give the illusion that it is an old retro-styled 2D platforming game. The twist is that the world is actually 3D for which you can rotate its view to look at the world from a different perspective. Unfortunately, nobody has ever tried or tested the game, as it's not even out yet. It's still in development. But who knows when the game will finally be released. At least, however, the entertaining physics-based drawing game called Crayon Physics Deluxe is out after many months in development.
All of these games provide a unique form of entertainment unlike anything we've seen in today's big franchise games. Yet all of them provide a sense of good value when it comes to purchasing it, for they are cheap and is worth the money spent. It is too bad I cannot say the same for some other titles, where the cost is 50 to 60 dollars at retail.