How to make a game like topple over?

[rafael_unity477]

Hey guys how did they make this kind of game.

here is the link to the game
‎Topple Over! on the App Store

1. how did they make it run pretty smoothly on a phone
2. how did they activate the blocks to make then fall nicely when they are struck.
3. how do they detect how many pieces have fell on the ground even if i lands on a its own destructable block it still manages to detect it.
4. how did they manage to do the nice starting animation of the blocks spawning.

[TheFloatingSheep]

• It looks like they only use a few
  differently sized blocks with very
  minimal color variation. If the mesh
  is identical and the material is
  identical, GPU Instancing would make
  it run a lot smoother than it would
  otherwise.
  Unity - Manual: GPU instancing

---

• As for the performance of the
  physics, it’s possible to write that
  into a compute shader and have it run
  a lot smoother than it would run on
  the cpu, but I highly doubt they’ve
  done that in this game. Rigidbodies
  would probably work just fine.

---

• As for the animation, assuming these
  blocks are stored into an array as
  they’re loaded, they could be stored
  in order of their Y position,
  straight as they’re loaded from
  something like a json file, or if
  they’re just plain prefabs they could
  be ordered based on their Y value
  from lower to higher being top to
  bottom of the hierarchy. And then
  you’d just need to write a coroutine
  with loop and break of half a second
  or something, going through all of
  the items of the array or the
  children of the parent prefab which
  you’ve instantiated and do SetActive
  on each one of them. It’s pretty
  straight forward. I downloaded the
  game just to see how the animation
  looks, was expecting it to be more
  complicated.