I seen some people playing PC games with the onboard video chip found on an AMD and Intel CPU on low settings, so I feel many games could work on low video quality settings.
I think for certain games like 2D games, flash games, older games like Warcraft 3 and classic games like Doom, and Lemmings for PC, they maybe playable with the onboard video chip which is built-into most Intel Celeron CPUs. But, the Intel Atom maybe too slow for some flash games and older PC games.