This is amazing. The concept is really solid and the game is very polished. The mechanic of having different colours stick better to each other is really clever and even meaningful to real life.
Big respect for doing a VR game and risking not clearing the 20 rating mark. It really paid off though, I could absolutely see this being a storefront game.
I think 5 lives is a bit too easy, I would suggest even just making it instant death if anything falls off. Often when one falls off, the tower has bent to the side anyway and all my height is gone, so I'd want to restart.
I can see a lot potential for expansion/more levels by introducing more colours of turtles, and turtles with special abilities such as stronger turtles and turtles that can hold on to more than one other turtle. Or if all the turtles can hold on to multiple by default, you could have multiple "base" turtles etc.
It reminds me of bridge construction games, so I think there could be some sources of inspiration there for further development.
I've bookmarked this, definitely interested to see if you develop this further!