The story is based around the war on Nu-Earth where a group of G.I. (Genetic Infantrymen) were betrayed by a traitor General. Most of the platoon was slaughtered, but one still lived on. Collecting up the dead troopers bio-chips, this trooper then turned rogue, and vowed to avenge the death of his war brothers and kill the traitor General.
The battles are set over four levels combining different styles of gameplay. Initially you need to escape from the Nort prison in a beat-em-up (and shooting when possible) style gameplay until you find your way out and then proceed to the next levels where you fly on a spaceship and battle with airborne hostile crafts in a Space Harrier gameplay!
In the 2D levels there is quite a lot of interaction with the backdrops. You collect several items and need to operate certain spots in order to unlock doors and collect advanced weaponry and armor. Each level is full of nasties varying from human armored guards (the Norts) to flying robots. You may collect money too, in order to be spent for buying extra armor. The flying levels are the next part. Those are ala Space Harrier gameplay-style, which involves flying low and fast over Nort territory. Credits are collected for destroying incoming enemy jets and this are increasing the power of your puny craft!
Rogue Trooper is a good game and worth a look. It offers great gameplay with some good looking graphics and sound although a little more variety in details and music would have been better.
The Atari ST version offers similar level and sprite details as the Amiga version but with fewer colors and some gameplay flaws. Sprites are nicely designed and pretty well animated but background scrolling is straggles when too many sprites occupy the screen. There several details in the interior levels (but repetitive) but a little more variety in details would have been better I believe. The flying levels ala Space Harrier look great with some impressive colors but with fewer levels of parallax-scrolling here, when compared to the Amiga version, due to ST hardware limitations.
Sound is great here, offering a lot SFX (but not sampled) along with some great in-game music which is totally different than the Amiga version, but is also one of the best I ever found for an Atari ST game.