I was browsing random files in my gg2 folders and found that I had an old training mod (06/2010) for GG2, where you are a soldier shooting jumping scouts on ctf_truefort.
Since that mod was completely outdated, and really not perfect, I thought that would be a good idea to make my own and see where it goes.
So there it is:
Gang Garrison 2 - SOLO TRAINING MODDOWNLOAD LINK - v0.3.3.2contains .exe, .gmk, readme.txt, a Music folder with three new sounds, and a Maps folder containing a custom test map and a .npc file
How to play:
Start the game - select a class - select a map - you're done!
Note that this is a WIP. There still are a lot of scripts missing, etc.
Screenshots:
Features:

Bots

Gunspinning

Dialogs

Intuitive menus

Scenarii and events

Game over

Maps are only playable by a specific class

Custom map support

NPC editor

Good maps

< done;

< in progress;

< to do
Changelog:
0.1.0 -> First commit
+ Added a "game over" feature
+ Fixed infinite ammo
+ Fixed endless errors when maps ends
+ Fixed game over
+ Removed debug things
+ Added all Character scripts BUT SPY AND CURLY
+ Added a bot behaviour (STAY: the bot moves very close to its spawnpoint, only shoots when someone is seen)
+ Fixed player death scream when map ends
+ Removed unneeded extensions
+ Added maps runnable by a specific class only
+ Fixed a mistake in map-linked-to-class system
+ Re-fixed player death scream, when abort / restart
+ Fixed character selection, not displaying the selected class
~ Improved bots
+ Made arena mode usable
+ Added a new map - medic_lumberyard
+ Added a new music
~ Fixed(?) multiple "game over"
~ Fixed hole detection
~ Attempt to add cliff detection
+ Added npc teleportation for scenario purposes
~ Modified spy_conflict - overweight now comes when sentries are destroyed, constructors will rush you when you get the intel
+ Fixed restart
~ Fixed bots following you when invisible
~ Improved obstacle avoidance
+ Added cheat menu
+ Removed a show_message in character step event when ubered
+ Reskinned the dialog box
- Started a noding system for complex bot path-finding. Not completed at all
+ Added Blue team playable
+ Fixed medic's AI
+ Added heavy_dirtbowl mission - defend the last point as blu
+ Fixed teams being swapped forever after starting a mission as blu team
+ Fixed character selection