Take on a somewhat meaner version of the Second Encounter, courtesy of Laz Rojas.
If you're in a mapset mood, or Laz mood, here's a pretty sizeable morsel for you. Laz's 2nd Encounter! The game's exactly what it says on the tin, thirty maps that serve as Laz Rojas' own variant of the new Mac maps. I believe it's a rather early release, so not all signs of trademark Laz mapping are already there (notably less symmetry, generally fewer enemies, for example), but it's still a notable release.
There was no documentation coming with the mod and Laz's website only says "When the original thirty levels get too easy for you, try these on for size", so you're free to just plunge right into playing without a second thought.
===CREDITS===
Laz Rojas