Pretty good little game, would make an excellent mobile game with tilting and touching screen to rewind. Loved the music
I Found this weird bug were my character suddenly disappeared when i got over 500 score
and the Fixed resolution made it hard to find the options button (it was behind my taskbar)
The enemies Spawn only on the sides, never the middle
also, if you press rewind long enough, it affects blocks that arent on screen, and when they come, they cant be rewinded (because of the 5 seconds). I think that you could add a condition to make the rewind only work when the block is below a certain point in the camera (using MainCam.WorldToViewportPoint(Obstacle.transform.position).y Which will return a float between 0 and 1 when the Obstacle is inside the camera in the Y axis)
And i also couldnt figure out what the number up on the right represented
I enjoyed it very much, good job:D