Best mods as Standalone Games of all time

[RobotSquirrel]

GMDX?

pretty sure the critera was Mods that could be Standalone Games so Total Conversions. GMDX would not count because its closer to an expansion. TNM was a total conversion and one of the best for Deus Ex.

 

[Elthosian]

Another Metroid 2 Remake is not exactly a mod but it deserves a mention, loved that one.

 

[Gostak]

https://rpgcodex.net/forums/threads/notable-total-conversion-mods.141626/
Repeating from there:
Action:
ThieveryUT (UT) (MP has long died down, HRTF/spatial audio hurt it IMO, has bots for the guards)
Movie Battles II (Jedi Academy) (active MP class-based)
Alien Swarm (UT2004) (by makers of ThieveryUT)
Infiltration (UT) (bots are not fun)
Meta Ball (UT2004) (SP MarbleMadness like action / puzzles)
Troopers: Dawn of Destiny (UT2004)
Philip Muwanga's Squad Commander (UT2004) ("real-time strategy")
Golden Eye X (Perfect Dark romhack)
Aliens: Eradication (Doom II)

Sports:
Deathball (UT2004) (online community died down, there was an ugly standalone version SupraBall)
Unreal Open (UT2004) (kind of like what Deathball did for soccer just here for tennis)
Carball (UT2004) (Rocket League turned this into a game basically)

 

[Baron Dupek]

UT... I remember some big mod that introduced mechas (like MechWarrior size) flying jets (but more futuristic/alien) and massive levels with pyramids (also more futuristic/alien).

Got from my cousin or random CD, never managed to find them online...

 

[Nifft Batuff]

Every game made in Unity or Unreal should be considered as mods.

 

[Gostak]

UT... I remember some big mod that introduced mechas (like MechWarrior size) flying jets (but more futuristic/alien) and massive levels with pyramids (also more futuristic/alien).

Got from my cousin or random CD, never managed to find them online...

Original UT?
Sounds a bit like Neo Cairo then (Mechs there are kinda small, though):
https://www.moddb.com/mods/neo-cairo
https://ut99.org/viewtopic.php?t=14241