Got the game on the 28th of May 2015 and despite my worry of the graphics and complexity expressed in reviews and on the forum it turns out I have been missing out on a gem of a game in the Turn-Based Strategy genre.
I simply want to add to the list of positive reviews that I am satisfied with the game thus far. Yes, I did have to read the manual but reading the manual and playing the game goes hand to hand if you are in to that sort of thing. Other reviews will help you better gauge what to expect from this game. For now I simply want to write a positive review for this game but do plan to update my review once I build more hours and try different maps and factions as well as different strategies.
edit: at 43 hours I've concluded and upgraded to Dominions 4. I started off with Dominions 3 to gauage how good this game seemed to be from the forums and since it was cheaper at the time of purchase. This game is still great, I enjoy the 2d graphics and sprites and the soundtrack is top notch. Dominions 4 however has a smoother UI and updates on the factions (even having slightly more factions) and more spells and since I completed the tutorial and played a few other single players in Dominions 3 which I thoroughly enjoyed I figured it was time to upgrade when the sale came around. Overall I give this game 10/10 for being excellent for it's age (this game was released in 2006). Dominions 4 adds and builds on what dominions 3 was missing. Clearer sprites, stats, and and much more thorough manual (even more thorough than the manual provided with Dominions 3).
I would highly recommend this game on a sale since it would make sense to jump right into Dominions 4 especially with it's handy dandy 400 page manual.