/vr/ - Retro Games

I have total block for my current map. I thought of submitting it to DUMP, but I am not even finished with the rooms.
I only had a general layout idea, but then I realized my rooms are huge and empty.
This one for example is supposed to be a trap. You try to grab the blue key and then monsters spawn, with the real key being in another room.
However, I really don't know how to set up the trap. Bars? A nukage pool? Just a few corpses around the key? It's all shit.