itch.io

Yes, so the gates react to gates as well as items, so the orange gate sees that the red/blue gates are closed and reacts to that (and stays open because it's inverted), and then when red and blue are open, the orange gate no longer sees them and instead sees the item underneath (which it reacts to by closing since items always give a true signal and the gate is inverted).

The yellow part of the logic gate doesn't have collision detection when placing the gate, so you can place it over anything. Open logic gates also don't have collision where the yellow part would have been, so you can place things overlapping that.