I've played the 16 level demo of this total conversion mod and had a good time. A lot of attention was paid to make sure that the mechanics of ZAMN work in this FPS framework. It's a very functional gameplay.

My problems come from what doesn't need to exist in a top-down game versus a first person shooter. There is a lack of sound effects for monsters. These SFX were in the original SNES game but in a first person shooter where you don't have a good range of vision around you it's good to have sound effects for monsters when they are approaching or spawning.

The ammo rates have been changed to accommodate a different perspective. Ammo for the water gun is reduced because you'll likely be deadlier with the weapon with first person aiming. There's still a lot of awkwardness in this game but I had a lot of fun and these level conversions are near spotless. There's also original levels that take advantage of the game's verticality and 3Dness that really let the idea shine.