The 3D and time travel mechanic is impressive although on my setup, it took quite a while to respawn after dying, also the game froze for a few seconds on the browser when you first encounter and kill a particular mob.
I found the key in each of the two runs and I feel killing the mobs was the main part of the gameplay, it would be great to see it fleshed out and see the paradox mechanic affect the gameplay if this were to be developed further.