MapStuffs is a WIP plugin that allows players to replace sprites and sounds on certain maps.
For example:

...On MvM maps, you could set the character sprites to Mecha sprites, then have the original sprites be used afterwards on other maps.
(The weird shoulder thing that happens in the second half of the gif is due to the sprites using the same transparency color as the shoulders...

)
I plan on adding support for music to play during specific maps as well.
So, how can this be used? Well, map-makers can provide links to custom sprites/sounds/etc. in order to enhance the map in various ways. An example is making a feudal-age Japanese-styled map, and making the characters and weapons into Samurais and crossbows, respectively, as well as including custom music. Or, as shown above, using MvM sprites on MvM maps.
1. Make a folder with the name of a map in the "MapStuffs" folder.
2. Add the default versions of your sprites/sounds into the folder, with a "_O" at the end of the filename.
2a. If you have a folder called "Sprites" or one called "Sounds" in your plugins folder, MapStuffs will load from that instead.
3. Add your custom versions of the sprites/sounds into the folder, with a "_N" at the end of the filename.
4. Start your server/join a server and wait for the right map to start.
Your setup should look something like this:
Custom sprite: Gang Garrison 2 Folder/Plugins/MapStuffs/2cp_kulay/PyroBlueRunS_N.png
Original sprite: Gang Garrison 2 Folder/Plugins/MapStuffs/2cp_kulay/PyroBlueRunS_O.png
The reason you need the original sprite in the same folder is due to the fact that this plugin replaces sprites.
If the originals are not reloaded, the sprites will carry over to the next map.
TODO:Add support for Spriteloader by loading from the Sprites folder instead of originals 
Add custom sounds support 
- Add custom music
- Provide options ingame
- Add button to reload sprites ingame
Sprite Packs:
Example sprite pack:
[link]Changes Quote/Curly's Bubbler/Blade into green and red colors when playing on the map ctf_truefort.
ctfpyrotennis:
[link]Changes Flamethrower into a tennis racket and flares into tennis balls, as well as changes the jump sound into Cave Story's jump sound. For use with the map
ctfpyrotennis.
Preview: