I really liked the Unreal series of games and this was a gem. A steal for this price with all the updates. It's a fun game with pretty good graphics and design and is fun to play. This and Unreal II The Awakening were two of my favorites. One of the first games to have decent water effects. I agree with the other reviewer, better than Quake series (though I liked them, too). One reason I say that, is that I found the Unreal games to be more playable, as I could progress at a steady pace.
Very happy to see GOG add these fine games to the mix!