Fester begins his quest in the middle of a city street cast in a most Legend of Zelda-like perspective. He'll have to collect weapon power-ups and items while dealing with low-level alien agents such as the frog boss from Sunsoft's Blaster Master making an uncredited cameo here as a series of increasingly strong basic foes. Fester's march through the overworld is accompanied by this theme, a rousing march of a song that practically shouts "Let's go!" even when players are blocked by a frustrating dead-end or unpassable barricade.

If Fester could lurch his way directly across the overworld to the alien UFO then this would be a very short game. Fortunately for those who like inexplicable barriers, the overworld is loaded with blockades that prevent Fester from taking the direct route. He'll have to venture through the maze of sewers (which are, like the overworld, broken up into chunks with well-placed walls) which are loaded with rats, bugs, slimy aliens that steal power-ups, and Langolier-type beasts that can cheat the maze by chewing through walls. Sewers lack any kind of natural light, so provided Fester has some lightbulbs in his inventory, he can stick one in his mouth to light up the area (the game lacks the technical capabilities to animate that trick, but it's implied).  The grueling sewer theme highlights Fester's journey.

Breaking up the over/underworld dynamic are sections of 3D mazes that are navigated a screen at a time without the benefit of animation to indicate where Fester is and where he needs to go next. I spent too much time wandering around in circles and inadvertently backtracking my way through these mazes as a kid, and this strangely tuned theme played in the background the entire time.  It's not often that I get lost in a maze-like gray-walled building, but when it happens, I still hear this music in my head while I'm searching for the exit (and I usually do backtrack around to the entrance by accident).

The end of the 3D mazes give way to a boss encounter where Fester needs to find a safe spot and shoot and/or whip repeatedly until the monster in question dies in a sequence cribbed right out of Blaster Master. The game's basic structure is as follows: overworld → underworld → overworld → 3D maze → boss attack → repeat. Here's a little boss battle riff for your enjoyment.

Eventually Fester will stumble across the UFO and venture inside for one last sewer-type underworld level packed with just about every minor foe encountered in the game thus far. Destroy the alien hivemind to win the game and activate this strangely melancholy victory theme. We won! Shouldn't this be a cause to celebrate? Those Addams folks always were a bit on the strange side.  At least the townsfolk appreciate what has been done for them.  Burning the creepy family at the stake can wait for another day, I guess.

We've come to the end of Fester's jaunt through Beyond Beeps, so that's Game Over until next time.