apply these steps:
if you have moveable character then use lightprobs:
bake scene:
use occlusion culling:
then turned off lights after baking. you will see big difference
I see some tutorial using SpriteManager with “Transparent/Vertex Colored”, but it’s very slow for iPhone (and I don’t know why, Device.Present needs more time, maybe a problem with the video bus, or something else).
So I used the speed shader of Unity like “Mobile/Particles/Alpha Blended” and it ran better (I won 20FPS).
I also optimized the batch render of Sprite Manager and reduce the culling by deactivate somes Game Object not on screen (I won 3ms by frame).
At the end, I didn’t need “Good” Quality Settings, so I changed it to “Fastest”, but I kept “Texture Quality” on “Full Res”.
Some people said to change “Script Call Optimization” (Player Settings on iOS) from “Slow and Safe” to “Fast but no Exceptions” but it maked my application crashed. I will look for this problem later.
With all of that, my game run at 30fps on iPhone 4, iPad 1 and 2, and ~25fps on iPhone 3GS.
Now I’m trying to reduce the Game Object count (I have 2400~5000 by level).