RFTG is a quick, but deep game.
On the surface the mechanics can be thoroughly learned in few games, but to really understand how to win against a good opponent (playing one of the
basic strategies) is fairly difficult, and essentially requires you to execute one of those 4 strategies.
These strategies really boil down to figuring out the most efficient way to build victory points given the cards you draw, combined with guessing what the other players will do, based on what strategy they seem to be executing and choosing actions each turn that both give you the most benefit, and give them the least benefit.
I have played about 20 games vs the AI, and managed to win only 1. I doubt I will play against the AI much more, since it really is frustrating, but I would have no problems playing against people.