It would help if the moveable platforms could be painted as well. (Had one too many cases of the ' air' next to the platform's black stripe being indistinguishable from its top-side.)
I'd aslo like to be able to paint slopes downwards. (at the moment it only works when painting them upwards, preventing one from noticing a hole in the slope until it is too late if you're climbing down from it.)
but the concept is GOOD.