A decent action title that makes good use of the original Gameboy to provide adequate entertainment.
Throughout the game you will play through multiple levels, encountering various alien types, chestbursters, face-huggers and eggs, areas with acid dripping from the ceiling and such. In each level you will obtain multiple weapons that you pick up in on the ground in each level such as bombs, the shoulder cannon, the spinning disc and others. Each weapon has different ranges, power and number of uses.
Graphics and sound are obviously dated, since this is an original Gameboy title. However, for an original Gameboy title it looks and sounds quite good, and for its time it is relatively high-end. The controls are relatively tight and easy for most anyone to learn and the gameplay is rather tight. Enemies will become harder to kill in later levels, requiring more attacks to take them out and some strategy will be needed. Such as when to use a screen clearing bomb, when to use invisibility (which will drain your energy meter, and if that hits 0 your map will vanish and you'll have a harder time finding your way around), and at what time to attack enemies (enemies such as chestbursters will be hard to kill if you don't get the timing down). The levels are set up decently, maze-like areas where a key is hidden in one area, and a locked door in another. Once you find the key, you can then unlock the door and move onto the next level. Now-a-days it is a rather simplistic mechanic, but it is still a mechanic that will provide fun even today.
All in all, it is a decent use of the Predator and Alien licensees on the Gameboy, however the dated graphics, sound and playing mechanics will turn off some people, and the repeating enemies and only having 4 different types of weapons plus invisibility may turn off others who are looking for a more evolved and deep experience, but for what it is, an old, original Gameboy action game based on Aliens and Predator, it serves its purpose and if you are willing to enjoy an old-school action game that is not as deep as action games have become today, it is a fun diversion that will be worth a play-through.