This game has lasted years on my machines.
I have paid as much for prettier games that didnt last a month on my machine. Especially irritating if Ifind a killer walk-thru is posted somewhere right after I buy the game. Dom3 has been out for years and the forums are still arguing strongest/weakest, tactics, etc. And no cheats, no backdoors.
Dom3 had 63 nations (now 72 in the patched game). Unique nations with unique abilities and unique units. Not just same army wearing different color uniforms. Even within ONE nation there are at least half a dozen different popular strategy paths that have developed. Do you know how long it would take you to even figure out which one you like well enough to TRY playing multiplayer against others?
If you DO get burned out, there are still the unusual strategies to try and surprise people with. OR adding more of the many modded nations that players made, or special maps that add twists to the playing.
BUT (DISCLAIMER) Do NOT take my word for it. It is NOT everyones game. Definitely try the demo first! Especially now that you can go to the Illwinter.com site and get one that has all the patched improvements in it