NEDM Avenger is a single player game where the player controls a hovering orb of destruction resembling a cat's face. The player will be given a mission at the beginning of each level - mostly having to do with saving NPCs (kittens) and/or destroying a certain number of enemies (nazis). This is a very different type of shooting game - the player has infinite health. Instead of worrying about losing health, the player's sole focus is on completing the level within a certain time. The players score at the end of the level will determine how well they did, and the game's difficulty will adjust itself accordingly - the mission objectives may become harder or easier.

There will be three main weapons that the player can use, each with infinite ammo, but each having a cooldown time. Lazer vision, which has the shortest cooldown will shoot a target instantly, setting it ablaze and possibly causing an explosion. Firebreath, which has a large AoE will set all targets on fire, and has a slightly longer cooldown. Finally, the Chapstick Missiles, which have the longest cooldown, will explode for massive AoE damage. A special Powerup will effect these cooldowns.