The Halloween Sale is not that great of a sale and not much filtering capability. The store also tends to not have Mac version of games whereas Steam store will have them. So I guess I'm just looking for interesting games regardless of price.

Surviving Mars ($10.20, 66% off) - Sim City on Mars.

Observation ($10, 60% off) - As the space station AI try to discover what happened to one of the scientists.

Genesis Alpha One ($12, 60% off) - Space exploration rogue like FPS action and ship building.