This is an interesting one, although not really a great one.
The world and lore it establishes are well-done and interesting. You get to encounter different sects, and you can ally yourself with them, betray them later, and then change your mind and do what they probably would have wanted if you hadn't already massacred their town. All of these actions have consequences within the world and how that world reacts to you. Those consequences follow through all the way to the ending of the game, which has a pretty impressive variety of outcomes. This is probably the strongest part of the game and what makes it worth playing through.
The growth and progression of your character is also well done. You can choose to play Geneforge as three quite different "classes". Every level up you get a set of skill points that you can apportion as you wish. The class you choose doesn't dictate what you can do, but it does make it easier/harder to level up certain skills. Skills range from physical combat, magic spells, the ability to "shape" creatures to fight for you. General skills, such as Leadership and Mechanics, are also available. Pleasantly, these are actually very useful to find non-combat methods to progress through the game.
Again all of these things are well done, and are what make the game worth playing. Where it falls apart a bit, is in the interface and to a certain degree, the combat.
Combat is turn-based, and on the surface, can be quite tactical. Timing, and awareness of the positions of both your allies and your enemies are all quite important. Particularly, when you do have allies (such as the creatures you can "shape"), you do have to take into account whether or not you or your creatures are blocking a path forward. You can use this both to your benefit and your detriment, by funneling enemies down a corridor into one of your stronger creatures.
In theory anyway.
The problem is that, at least in my experience, the game is rather easy. So, tactics more or less go out the window, when you can just click-click-click your way to victory. Positioning at that point becomes more of an annoyance, as you try to coax the pathing algorithms to make sure that you don't waste a turn because you clicked slightly to the left of something, so it paths all the way around and your turn is wasted. And it's even worse that the punishment for this is not death, but a test of your patience, more often than not.
Towards the end of the game, the challenge is upped, but by presenting annoyances, like poisoned areas that do damage to you and your creatures for just being in them. There is an optional area towards the end that serves as a pretty robust challenge, but again, the tactics aren't really that interesting at the end of it. It's more a battle of attrition that you just need to push through.
Overall, the combat side of this game seems like it would be great on paper, but it ends up being boring most of the time, and annoying some of the time. Very rarely is it actually much fun.
I should mention that the presentation of the game is quite old-school, and to top it off, there is no music aside from the title screen of the game. You just get some ambient noise in towns, and sound effects for all the actions. That's it. Honestly, some music would have made some of the more annoying slog parts of the game much more palatable. I mean, it helped a lot when I was just listening to a podcast or some music when I was doing it.
That being said, despite all the gripes, I would still totally recommend the game. Normally, I'm a gameplay over story/presentation guy, but in this case I can overlook it. What it does right, it does very well.
From what I've heard, the series just continues to build on itself as it goes on. Based on what I played, I'm very much looking forward to eventually going through the following games in the series.