First of all, congratulations!! definitely an amazing achievement for the first game. The graphics although simple, are well done and fit the game well. Main mechanic is interesting and fun to use. The only small thing is, I kinda assumed it would be holding the mouse button to reveal reality instead of having to press twice. However this is just my opinion, and there's no right way, I just think it might feel more natural. Also there was no audible indicator when you switch between real and dream, which made me unsure if I turned it off or not. It could also be nice to have an audible representation of the timer, so that you don't have to constantly look at the corner of the screen (e.x. increase pitch of a sound as the timer approaches 0, or make a repeating sound repeat faster). As others have already mentioned, it is a little annoying to put the box on the button. It should either be a flush with the ground, or a trigger that doesn't really collide with the box, just goes down when the box is on top.
The only sort of bug I encountered is that the enemy doesn't show on the "real" circle, but you still get hurt by it, so I think it should.
In conclusion, a fun game with a nice concept, keep it up!
Also, if you have time, I would love to hear your thoughts on our game as well :D