Portal

Check out this trailer for the upcoming game Portal, from Valve, the developer who made the ever so great Half-Life 2. It's based on the same engine, which is the Source engine, which is renowned for it's successful implementation of physics into game mechanincs, rather than just as a gimmick. Now they're taking it to the next level with Portal, which as far as I can tell, is entirely based around the use of a gun that shoots portals to bypass various obstacles. If Valve can add some more good looking games like this to it's Steam catalogue, it might just prompt a bigger shift towards online distribution than what the state is at currently, which is leans heavily towards retail sales at the shops.