Mods that change how the enemies look and/or the sounds they make, or they are somewhat related like the Random Blood. These are purely cosmetic and don't affect the base gameplay.

There are just the Mr. Bucket Mechs that make it impossible to see the latched on C4s.

Some of the items don't work together, hence why they are often grouped together where you can choose one.


Other things to note:
-A crash can happen if you load a level that has a bunch of mods that may have been uninstalled or replaced, but the fix is simply to begin the level in question through the New Game option, then you can load your save fine.
-If you load a save as a different Player Model it was originally saved as, it can cause a crash, it may not be related to the mods below. It's possible to load a save that had the first character while playing as him/her/it, pick a different one, then reload that same save and it works fine. It also seems that, if you load a save as normal Serious Sam, it fixes the problem for when you load other saves in that session for some reason; do that, then you can play as any characters and load any saves without a problem.
-Enemies that are on the playfield in a save may cause the game to crash or not load the level if you installed a different model on them, but the weird thing is it's sometimes, I tested with the small spiders and I don't have that problem with them, but I did it with the Kleers and it doesn't load.