1. Oni - PC2. Donkey Kong 64 - N643. Yoshi's Story - N644. Neverwinter Nights: Shadows of Undrentide - PC5. Forsaken 64 - N64One of the few six degrees of freedom games, Forsaken came out a few years after Descent and was clearly inspired by what Descent did. But the game actually manages to do a lot of its own stuff and comes off as a distinct game rather than just a Descent clone. Also, Duke Nukem does the narration, which is always awesome.
The basic story of the game is that Earth's defense AI went batty and went on a rampage and humans fled to the stars. Now people, including your character, head back to try and destroy the defense AI. You pretty much forget about most of it a couple of levels in, though it does get mentioned in the level briefings. The levels themselves have a lot more variety of objectives compared to Descent. Descent was all about finding the keys to get to the boss core, blow it up, and escape. Forsaken requires you to sometimes destroy all enemies, sometimes you have to acquire an item in the level, there's an escort mission, a couple of defense missions, and a bunch of boss preview missions. These missions consist of fighting a boss, but when the boss gets low a beacon will spawn and you need to collect it and survive the onslaught of new enemies for one minute. These five boss previews then turn into the boss rush at the end; at the point where you would normally unlock the beacon you instead move the boss into his "go to the death trap" pattern, and you have to activate the death trap to kill the boss.
Several of the weapons are inspired by Descent. Your base weapon is a standard cannon. You have a machine gun that is high damage but fires slow shots with poor accuracy, so it's best for point blank. There's a chargeable gun that does a lot of damage when fully charged as well as an instant hit beam laser that has an overheat mechanic (though it's incredibly generous). Finally, there's a reflecting shot that has a very smart reflection; it seems the deflection angle is always calculated to aim at a nearby enemy, which makes it very useful for doing corner attacks and dealing with evasive enemies. All of these weapons are powered up by a universal power pod system, where you start with one and can collect two more. There are also a variety of secondary weapons; dumbfire missiles, homing missiles, giant nuke, rapid fire missiles, impact mines, mines that shoot missiles at nearby targets, and a homing missile that doesn't do much damage but forces enemies to drop their powerups if they're a biker (enemy PC) or spawn some powerups if they're a normal enemy. Finally, you can collect up to four orbital guns that fire when you fire your primary weapon and add a good deal of additional damage. These orbital guns seem to have only a limited number of shots to them, though there's no indication of what that might be.
Unlike Descent you start every level fresh. The nice thing is that you don't end up hording the good missiles because you lose them at the end of the level anyway. The annoying thing is this means the very first thing you need to do is find the first power pod of the level. Your weapons are extremely weak without that first power pod. Most of the time it's right near where you spawn, but sometimes you need to fly past a few enemies which can be a bit harrowing when you're flying blind into hostile territory hoping to find a way to do damage. This also means the final boss is a right bastard, as he spams the homing missile that makes you drop your powerups (including power pods) and that homing missile has a really tight turning radius. You tend to get caught into a cycle of getting hit, trying to collect your powerups and immediately getting hit again.
The biggest thing that was frustrating is the game doesn't give you the option of saving after every level. Instead, certain levels give you a save option after you finish. You do have the ability to replay missions, so you CAN save after every level, but it forces you to replay a level to do so. And none of the levels that let you save are especially quick to beat. The game also features a lives system and those lives don't regenerate after each stage. This ends up being the real difficulty in getting through the game unless you're willing to abuse the fact that the first stage in the hard path has two lives available that are both pretty easy to get; you run into the level, grab both, lose (as it has an defend objective) and you net one life.
Oh, I guess that bears mentioning. The very first level of the game is your difficulty selector. If you finish in longer than 2:40 you go on the easy path, between 2:40 and 1:40 you go on the medium path, and less than 1:40 you go on the hard path (which has the final boss of the game). At the end of the easy and medium path the game tells you how to unlock the next path up and mentions a few levels you want to be aware of, and from a story perspective you want to play through all of easy, then all of medium, then all of hard, as they all build to the final confrontations of hard.