Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.

Trainer Options:

NumPad1: Add Gold
NumPad2: Add Mana
NumPad3: Add Evil
NumPad4: Reveal Map
NumPad5: Research All
NumPad6: Toggle GUI
NumPad7: Win Current Mission
NumPad8: Spawn All Monsters
NumPad9: Spawn Super Monster
NumPad0: Spawn Random Hero
NumPad/: Invincible Units (READ NOTES!)
NumPad*: Spawn Snots
NumPad-: No Skill Cooldown
NumPad+: No Build / Research Costs

Notes:
Trainer activation may take a little bit longer on this game. Be patience and wait for 'Trainer activated' sound.

Add Gold / Mana / Evil: Press hotkey to add more of it.

Reveal Map: Press hotkey and the map is fully revealed.

Research All: Press hotkey and everything has been researched.

Win Current Mission: Press hotkey to instantly win the current mission.

Spawn All Monsters: Press hotkey to spawn all monsters at the current viewed location. There needs to be room for them to spawn.

Spawn Super Monster: Similar to spawn all monster cheat but spawns a super monster which is incredible powerful.

Spawn Random Hero: Similar to spawn all monster but spawns a random hero.

Invincible Units: During mission / ingame press hotkey and all of your current units are invincible. This cannot be deactivated except of restarting the mission.

Spawn Random Hero: Similar to spawn all monster but spawns 20 additional snots.

No Build / Research Costs: While active most stuff do not cost you gold / evilness / toolboxes etc. Does not apply to room costs.