Short but very sweet! The music had majestic buildups on the approach and distorted spindowns on the escape, so that's awesome. The story was minimal (hourglasses = medicine?), but that didn't keep me from enjoying the puzzles.
I've played a few time-travel-twin games, but the notion of *reversing* time threw me for a couple of loops, and same for the range limit. Not only did I have to pace my steps, I had to assemble my plan back-to-front, which rebooted my brain. The first three caves were more tutorial than challenge -- fun but quick. But I didn't beat either of the last two in any hurry. The terrain was a lot harder to jump with a measured pace, and inverse of a helpful fan = a meat grinder... should've seen that coming, but didn't. Well played.
Mind-bending concept, if a bit short, and those dragon breaths sound like the ignition of a rocket engine. Very cool!