У вашего броузера проблема в совместимости с HTML5
Construct2 sample HTML5 game with effects enabled through WebGL running on an iPhone 4S using Ejecta.
Got around 6-7 FPS but seems fully functional. The sample game didn't have touch control - so the player is not moving.
This is probably the very first time anyone has run a Construct 2 WebGL game on iOS. I can definitely see a more mobile optimized Construct2 runtime performing better on iOS in the future.
Eject Github - https://github.com/phoboslab/Ejecta