Oh man, you've totally captured the weeping angels here. Nicely done!
The walking backwards mechanic is such a small but essential piece to this puzzle. It felt a little weird to use the first few times, but I got the hang of it.
Knowing weeping angels, I think I would have appreciated a slightly different "solution" style to the puzzles. Being able to defeat them by tricking them into spike traps is a bit basic for them. It'd be much more interesting to lure them into rooms and close the door or drop them into pits.
Overall, you did a great job on this. Well done and keep making games!