Here is no any information about successful running simple 2D games on low-tier 2.3.x devices.
Only thing what we know for now, is minimum API Level required.
Epic dont give any warranties about running UE4-based applications on any hardware except: Nexus 5, Kindle Fire HDX, Samsung Galaxy S4 SGH-I337.
So if you really run some simple game on 2.3.x device, please share your results on wiki page (or here), it will be very helpful! :o