Looks like Q.5 <- Q1 + inferior weaponry :p
looks good (and clean) for a Q2 map. At least it's not YASB. Will have to download and try.
After playing it, I have to say too much lava for my taste. The part with the "jumping through spikes hanging over lava" would be cool in an SP map, but in deathmatch there should be no jumping puzzles. While some strafe jumping or swimming is OK, 99% of the map should be reachable by just walking. Also 1 or 2 walkways across lava are OK (like in Q1's DM2 and DM4), but no more. Water would be better (used as an additional travel route like in Q1's E1M2).
I liked much of the architecture, though I think the map is lit too brightly and evenly. More variation in lighting plz. And another thing, when you have an open ceiling (sky), there's no need for additional torches. The light should come from the sky, and it's OK if that means a few dark corners. Shadows are good (look at Q1's DM2 and even The Edge).
I'm not too big a fan of the railgun either, but that's personal taste.
The map has strong points, the basic architecture is good, but work on lighting and don't overuse lava.