Atmosphere and avatar lab are geared towards web exploration games. I found the sample worlds on Atmosphere were more like hide and seek than anything else. If you want to get into games, there's a whole different arena in the Half-Life department such as CounterStrike game and the myriad of maps that folks make for it. I think I've seen a sky in one of the maps that reminded me VERY MUCH of a Bryce image. However, I don't use Bryce for anything in the gaming department. You'll want a low poly modeler and some of the mapping programs out there like Hammer if that's your goal.