The original Marathon series was a cornucopia of fun and challenging gameplay, engaging plots and complex puzzles. Its controls were revolutionary for its time, and its story was unheard of in the FPS genre, in fact, some aspects of Marathon's story are still a topic of debate, over 20 years after the game came out. And while it never reached the acclamation of its descendant, Halo, Marathon never the less remains a major stepping stone in the history of gaming. In the first game, you must battle your way across the colony ship Marathon, fighting off the alien slavers, called the Pfhor, rouge defense drones and exploding Sim-Bobs. In Marathon: Durandal, you are at the mercy of the AI Durandal, who has taken you to the Sphit homeworld of Lh'owon, where the only hope for stopping the Pfhor, as well as Durandal's attempts at achieving immortality, lies. Finally, in Marathon: Infinity, prepare yourself for a real Mind Screw as you battle across different timelines, working with your enemies and killing your friends as you desperately try and stop the Pfhor from unleashing the ultimate doom unto the galaxy. All of the Marathon games were recently ported to the Apple series of personal devices, so if you have the time, and want some sci-fi fun, do yourself a favor and get the Marathon trilogy. Oh, and keep a look out for the Wave Motion Cannon ;)
Bungie's rather under-recognized precursor to the famous Halo-series, which takes heavily from it's older sibling. You begin as a random security officer, answering a call for help from the colony ship, Marathon. But there seems to be far more going on then it seems, the ship has been invaded by an alien empire called the Pfhor, who seek to enslave humanity. The games go far more in-depth after that, which for it's time was an innovation for gaming as it was one of the first (if not the first) FPS game to have an in-depth story in game. The story and your objectives are told to you through terminals you find throughout the game. Manning them are usually on of the A Is (or Robert Blake) who perform the send you on your way. You have Leela, the only "good" A.I, in your encounter trying the use you to save humans on the Marathon. Durandal and Tycho are a different story, both have gone rampant and are extremely cunning to boot, Durandal in particular can come off as a wild card, with many interpretations of him depending on the player. Other characters appear on these too, such as the ever-enigmatic Thoth, the mysterious AI (with no stated name), and Robert Blake usually. Gameplay wise the game was also an innovator of it's time. The graphics were (for it's time) very good for starters. When it came to shooting, it was the first game to allow you to aim up and down, dual-wield, and have clips (though there is no reload button). There was something of a jump, but it was more of a glide and one had to be careful in moments where they traverse obstacles this way as you can "bounce" strait into the hazard if not careful. The story itself is very in-depth and thought provoking. With many things up for interpretation or strait up mindscrewing most players. There is even an entire website devoted to WM Ging regarding this game. Especially the third game (Infinity), which is Bungie's version of the C'thulhu mythos apparently. Brilliant games, and they are now freeware for anyone to download if anyone wants to try them.
Marathon Trilogy by Bungie
The Marathon trilogy is overall pretty fun, and more fast paced than modern games. The graphics are better most games from the time, but they could have done a better job. And the sound effects are mostly commonly used sound effects-nothing special there. These sound effects are so commonly used that they're in stuff from Final Fantasy XII to Metal Gear Solid 4 to Super Mario Galaxy to Bill Nye the Science Guy. The music in the first game is very impressive. As stated earlier, it plays fast. There are five difficulties you can select, which was a new for FPS's back then. There is a wide variety of guns. Unlike in DOOM, each gun can be used for different circumstances, rather than just having one or two guns to kill anything. In the first game, your allies consist of a bunch of retards who were told to arm themselves but decided not to- they'd rather stand in your way, and defense drones. You will more than not have to kill some to pass. Multiplayer is supported, very interesting plot. You're fighting aliens, but in Infinity, you fight humans too. Despite these humans being described as civilians, they're more dangerous than the aliens who were about to enslave humanity! How the hell does that work?! The plot is especially intriguing in the first and third games. In the first game, there are so many things that nobody can understand that they've made a website of these things: http://marathon.bungie.org/story/ Infinity (3rd), is a huge Mind Screw. You'll have no idea what the hell is going on except that you're stopping aliens from causing destruction that will kill both them and the humans. You're a cyborg wearing MJOLNIR Mark IV armor. Sound familiar? (Halo!) Anyway, here's the meat of the gameplay- Marathon: You're mainly in cramped and claustrophobic corridors with aliens and elevators working together to stop you from saving Earth. Marathon 2: Durandal: You're mainly outside or swimming. I highly recommend co-op on this game. Marathon Infinity: Sort of a combination of the two. Co-op is possible and in some cases, necessary. This game has different ways to beat it, but one ending. The 1st game has 26 levels, the 2nd game has 28, the 3rd one has 25 with 3 Vidmaster levels and 5 hidden levels. More info+Download: http://marathon.bungie.org/spoiler/ and http://source.bungie.org/index.php?title=Get_Marathon