Try to make one with Unity Editor, it's free.
Or you can try free online games such as uberstrike or other games and see if your computer can handle it by going to
www.systemrequirementslab.com/cyri/
It's not completely accurate but it's good to give you an idea if you can run a game or not.
For example, it says I can run Crysis better than Battlefield 3.
Although Battlefield 3 is very graphic intensive, Crysis is THE most difficult game to run.
Even my system gets strained on maximum settings.
But it judges it by looking at your system components and matching them to the system requirements of the games.
You might want to look at games like A.V.A., Counter Strike, Combat Arms, Halo CE.
Or for MMORPGs, you can try Lord Of The Rings Online (LOTRO), World Of World Craft (WoW),
DC Universe Online (DCUO) (it has batman and superman in it
) or Champions Online. (another superhero MMORPG)
WoW is now free for the first 20 levels, not bad.
