You control L.I.N.D.A. - the Laser Incorporated Nasties Disposal Android - who as you might have gathered is not a cuddly toy but a dedicated killing machine, specially created to clear the sewers of the assorted nasties that have taken them over.
You must guide her path through the sewers, killing anything that gets in your way and recover the eight grenades that are scattered around. When you have gathered a grenade you must take it immediately to the lair of the green slime. When you have gathered the final grenade, you must proceed to the lair of the green slime and use all of the grenades to destroy the slime completely. Failure to accomplish your mission will be regarded as cause for a full disciplinary hearing.