I love everything that reminds me of Portal xD I can see this being a full game with some lore and more puzzles! My only suggestion would be to indicate somehow where the drone is, or we should be able to summon it after entering a room and the door closing. I thought I was stuck when the drone stayed behind in the other room and the door closed, but then it reappeared after a while. Could even be a joke like "Oh, you lost another drone? Fine, here is one more" and then they give you another one and charge for the ammount of drones you used at the end xD
Overall, great game! Keep up the good work ^^