S.U.C.K. is a pretty versatile MacenWolf modding kit, letting you modify many aspects of the game with a simple text file.
Here is an all-new MacenWolf modding kit tentatively called S.U.C.K. To quote the included, detailed manual:
"Suck-ing is a super-easy method to modify the game and barely an inconvenience. Even your brother's dog can do it! It's limited in scripted scope, not overly complex and has some loose screws but lets you do quick changes. With some creativity it gives you enough room to turn the whole game upside down and all around. All you need is a text file, add some variables from below and rename the file to mod.cfg."
Therefore, in addition to the possibility of using multiple VSWAP files and sound folders, you get to modify a great number of parameters and aspects of the game (or a specific map, or more maps), all via a simply structured text file. The capabilities include:
Enemies: HP, damage, behavior, speed, enable/disable 8-dir rotations
Projectiles: speed, damage, lifetime, splash damage, knockback, homing properties...
Weapons and Ammo: nearly every damn aspect and property you can think of
Level Start: pistol start or not? starting health and ammo
Various Things: you know, stuff... things like enabling a countdown, changing player speed and max health capacity or enabling a 64x64 VSWAP
Static Objects: solid? pick-up? billboard? source of light?
Pick-up Items: change the good (or bad) stuff a pick-up gives you
Statusbar: enable, disable or move any part of the status bar
Additional Sprites and Rotations: make use of 12 currently unused objects, the fake Hitler enemy, BJ's running animation or add rotation sprites for enemies and bosses
Refer to the manual included with the download to learn specific details on usage.