Basically, Berzerk and Frenzy are the same game, but Frenzy has more to do. You not only go through many mazes with varying amounts of robots and firepower, but you go through actual rooms, each different. Plus, you can shoot through the segmented walls to create an exit, bounce shells (so can the robots) off of the solid walls, and shoot Evil Otto for points and make him dissappear, but beware because each time he comes back he moves faster than before, to the point you can’t out run him. If you stay in one of the rooms too long, another Evil Otto comes at you from a different direction along with the original one! Also, the robots are much smarter than in Berzerk.
Shoot at as many robots as you can before they come after you. Watch out for Evil Otto who comes in from where you started on the screen. Be careful of robots shooting through the segmented walls as well as there are not as many places to hide as in Berzerk.
In Frenzy, scores are usually higher since the game varies in difficulty. Berzerk becomes difficult very quickly, but Frenzy’s challenges seem to come in random waves.