I was thinking that you could find bonuses that helped you out, but they were things to do with stoner culture. Like if you found a bong it was some sort of power-up, maybe it makes you go faster?
Also I think some dialogue triggered by certain actions would make the game funny and could give clues as to what SDF is doing.
I was also thinking that maybe if you clicked on a certain part on the room you could zoom in, so like if you were in the kitchen you could zoom in to the draws and interact with them in some way, i think it would add i bit more depth to the level, without making the level too expansive.
Let me know what you guys think.
Cheers,
Greg