It starts out slow with Doom3 style drab levels, but towards the middle things become awesome with spetaculer looking levels. You can tell the Doom 3 engine gets pushed to the max with the giant canyons, underground Strogg fortresses and high towers with badass elevator rides. It will push your system more than Doom 3 did, I mean my 6800 will lag if I go over 1024 * 768 resolution. The plot twist is pretty cool as well; it's one of those rare shooters who's story will drive you to complete the thing, but as all ways, you get the standard hero saves the day ending. Overall, this game is better than Doom 3, but slightly below that of HL2. But yeah, it's worth buying.