Spell force, it's a unique gameplay, a mix of RTS and RPG. Okay, is that all ? Yes and no...
Many games claim to be a new model, a mix of genres, and mostly fail. Not Spellforce. The universe is rich, possibilities are huge, and the progression is very good. You discover new opportunities all along the game - with the new races you can control), your main character can be developed in many different ways. You really have new challenges all along the game, there is no feeling of repetition (the level design and monster design are really good too).
Yes, the end of game is a little bit disapointing, but you will really have good time with this game - especially for this price.
I was very disapointed by the add-ons because of the lack of "progression" as there is in the main game - when a part of the game is to discover what you can do. Theses add-ons assume you already know the game pretty well and just offer you new maps, but the gamer do not have the real feeling of playing something new. Most maps are good, but as a whole it lacks the immertion of the main game.
But you wll buy it for the original game, won't you ? :)