Thumper is a simple game but it requires you to basically turn left, turn right, or shields up very quickly. It is basically a reaction time test so very susceptible to latency.

I had earlier played assassin's creed in the private beta thing on an older laptop on Verizon FiOS. I did reach for the Ethernet cable most of the time but iirc it was serviceable even on WiFi because assassin's creed is less affected by the occasional latency spike. That or maybe Verizon FiOS where I was before in the city area has fewer connection problems than Comcast further out of a town.