I think Linux needs to tap into gaming by emulating an Android device.
There have already been suggestions to this effect:
https://wiki.ubuntu.com/Specs/AndroidExecutionEnvironment
-There's a growing pool of game developers both professional and amateur for Android.
-There would be a high degree of compatibility, given that Android OS is a Linux variant, most of the incompatibility would probably be due to which specific hardware you decide to emulate (Tegra2/3, Snapdragon, Exynos, ect)
-There are other hardware projects moving to take advantage of Android's growing gaming base- ie: OUYA.
-Granted the games would probably be slanted more towards 'Casual' gaming, and even the games that push phone hardware to their limit can't compare to PC gaming but given the issues with GPU drivers in linux this is probably a good thing.