This game was my childhood. Descent is a disorientating FPS where you could fly your ship at any angle or direction in a gravity free environment, where the levels are even more complex and confusing mazes that become easier and easier to find yourself lost and trapped as you progress further through the game.
The gameplay is uniquely stunning, feeling like a limitless 'Doom', where enemies can fly and turn in any direction, will hunt you through rounded hallways and open doors for themselves, and have an array of models, weapons, and fighting styles. You yourself control a spaceship completely free to fly any which direction. The controls allow you to tilt yourself as well as move directly up, down, forward, backward, left and right, as well as changing directions, which both allows you full flexibility and maneuverability and also makes navigation extremely difficult (in a good way of course!) As you progress, you will find upgrades for your ship's primary and secondary weapons, as well as temporary powerups like invisibility and invulnerability. Your ship, your primary energy-based weapons, and your flares run on energy, which can be found at power stations found in certain levels or are dropped by enemy ships. Your ship's protection is its shield levels, which can be boosted by finding blue shield orbs dropped by enemies and placed in levels.
The level design for Descent 1 and Descent 2 is unmatched by any other game; what better way to utilize a fully maneuverable ship as well designed as it is with levels that include limitless doors, rooms and hallways that flip upside down, turn left, right, up and down, fork and loop and do anything possible. The best way I can think to describe it would to be to take a piece of paper and a pencil, close your eyes, and scribble like a mad man in circles and all directions for 5 seconds then stop and open your eyes. With the ability to pilot yourself essentially fully "upside down", on top of flying through a completely three dimensional maze makes for some of the best 'dungeon crawling' possible. With secret rooms on every level scattered throughout the levels, hostages and upgrades to find, if you aren't a long time veteran of this game, you will find something new every time you play.
The general goal of most missions is to find the enemy reactor on the level, destroy it, and find the exit before the self destruct sequence of the base hits 0. The reactor is found by progressing through a three tier series of doors, the blue, the yellow, and the red. You will find the blue key in the primary part of a level, which will unlock the blue door.. which leads to finding the yellow key in the blue door's section of the level... which leads to finding the red key in the yellow door's section of the level. With the sheer complexity of the maps, this can prove to be extremely challenging to a newcomer. Once the reactor is destroyed, the entire mission will start shaking, making it even harder to navigate as well as rattles your ship making it hard to pilot while you find the exit. The exceptions to killing the reactors are the boss levels, but I won't spoil that if you've never played the game before ;).
Overall, this is an excellent game that was way, way ahead of its time. For the breakthroughs it made that had never been seen in gaming before, it deserved a lot more attention than it got. As a franchise, the second Descent, Descent II, was also very successful as it used the same style and mechanics as the first, in addition to adding more weapons to your arsenal, more unique enemies to fight, and way more complex and difficult levels. Unfortunately, Descent 3 took a turn in the wrong direction, experimenting with a new engine, level and gameplay style, and because of its blunder, the Descent series was discontinued.
This was in fact the very first game I ever played at 2 years old, and the first game I completed independently at 3. When my dad, brother and I got the second, it only got better, and some of my best memories as a kid are playing these games and using the map makers for my brother and I to build our own levels.
Bottom line, you need to look past the dated graphics and give this game a consideration. It is just that much of a masterpiece.