I would say the title is pretty self-explanatory, no?
So... 4 mods in a release centered around the number four. Perfect, right? Yeah, no. Here's a fifth one. Consider your day ruined. The mod's called Four Quality Levels and it offers four quality levels for the First Encounter. Your mileage may vary. They are certainly extensive though, so you get a lot of bang for your buck. Mild in difficulty (plenty of brown guards, but also with a boss on every map) and fairly rectangular otherwise.
===CREDITS===
Tomato1044
TSmoovy
Carloscont
Not entirely sure if these are three different people or three aliases for the same person, but possibly the latter. At least it's not FOUR names...