Android 2.3.5 and can't run 2.3.3 apps

[pcastanho]

Hi i have an android phone that is one ZTE Smart A7 and it has android 2.3.5 and my friend has this real cool game. https://play.google.com/store/apps/details?id=com.kiloo.subwaysurf&feature=search_result#?t=W251bGwsMSwxLDEsImNvbS5raWxvby5zdWJ3YXlzdXJmIl0

That requires 2.3.3 android i was wondering if some one knows why it doesn't or knows the solution.

 

Ps: if someone knows how to root this device can it explain me?