I'd say the game was pretty good. The reason it didn't get very high scores was that, well, it wasn't Unreal.
Very few elements of the original returned. You had the Dispersion Pistol, and the Skaarj, and nearly everything else from the game was completely different. No Nali. No Na Pali. No Flak Cannon, no Eightball, etc.
If it were named something else, it probably would've sold very good, and it probably would've sold better if XMP were included like Legend seems to have planned. But without those, there simply wasn't enough "Unreal" in it - it was like reinventing the wheel (Tekken 4, anyone?) and it simply didn't pan out.
Unreal III, if Epic has those sort of smarts, will be probably something like what people wanted all along.