Take one basic Pacman theme, set it in a three dimensional maze, increase the height and width of the maze walls to life-like proportions then, for that extra something, make the monsters as big as houses. This should give you some impression of 3D Glooper.
Very simple. All you have to do is race round a maze in search of large blue floor-tiles. Passing over a tile causes it to disappear and you score ten points. There are over 300 tiles so you have quite a bit of maze to ramble through. A few red tiles are scattered about. Crossing one of these enables you, temporarily, to be a monster muncher instead of a monster's lunch. The monsters are huge yet-like creatures, brown, furry and yellow eyed. They turn orange when you pass an elusive red tile. Unlike other games, no warning is given when they are about to turn back to their normal, carnivorous selves.
If you succeed in erasing all the blue tiles, you move on to a higher level where the gloopers roam in higher number.
A plan and innocuous "prepare to meet the Gloopers" message is all you get by way of an introduction. You are then shown the entrance to the brick built maze. The maze itself is graphically impressive - large size walls with plenty of twists and turns. Moving your joystick (the keyboard can be used instead) causes you to rush along at high speed, the vista changing around you.
There is no overview of the maze, and unless you have a superhuman sense of direction, there's no way you're going to avoid getting lost. The only help you're given is a small display at the top of the screen. This appears from time to time and shows the part of the maze immediately around you.
Other information given is a counter which tells you how many blue tiles remain, the high score and current score. You receive a one thousand point bonus for every glooper munched. Sound effects are fairly minimal: a whoosh as you pass over a tile, the menacing sound of munching and a crash when you hit a glooper.
Rounding a corner and coming face to face with one of these hairy horrors is the most impressive part of the game.
A good game with some of the biggest monsters you're likely to see.