If possible, setting of general darkness of level. Would require transition from 16 tables. Some of these features ended up in the two Blake Stone games, both used the Wolfenstein 3D codebase. Metal wall with the word Wasser on it. Can blow away, leaves water.
Green barrels blow up one square red blow up nine.
Walking over it activates stuff. Damages all who walk over it. Metal shards from blown up tanks. Rockets you can blow up. Add iron key.