Very good game, i don't play this single player, i only play it co-op with my mate in Aussie. Immense fun.
--Very easy to mod:
Modding this game makes the length of this game almost infinite. You can download so many maps to play by yourself or online with friends, you can add new weapons, vehicles, enhance the graphics, change sounds. You name it you can change it in OFP to make this epic game that much more epic.
Another reason this has lasted so long is that it was the first full blown combat simulator. ArmA was released some whole after but it was ment to be better than OFP only it was worse in almost every way. We had to wait for ArmA II before we got anything to continue the series on. The new OFP Dragons rising is not actually in the OFP series, its also not technically OFP at all, they just bought the name.