I'm really appreciated your feedback. There is a "gray spot" in every level scene, that "gray spot" has a limit above its head (but you can see it if using the spyglass), you can place yourself or rocks on that spot to increase its number to reach the limit. If the gray spot reached its limit, the "yellow spot" would appear, then you can step on that spot to go to the next level, so you can win the game by that way.
I think I need to write more description to tell people how the game works. I haven't do that yet because I want player use the Spyglass to search everything in the scene, and engaging them realize and solve the puzzles on their own.
Thank you once again my friend.