Blake Stone: Aliens of Gold
If I could describe Blake Stone in 4 words, those would be "Wolfenstein 3D in space". As prettier as it is than Wolfenstein 3D, the game is very, very reminiscent of it. Movement, shooting, the enemy sprites, the flatness of the surrounding scenery and other stuff in general are very similar to Wolfenstein 3D, which isn't surprising when the game is actually based on an enhanced version of the Wolfenstein 3D engine.
As such, you should expect a similar experience to Wolfenstein 3D; run around stages, looking for treasures and keys, gunning down a good number of enemies (aliens and space soldiers instead of Nazis), exit the stage, maybe find a secret level, finish the episode, tackle the next one and so on. Also like Wolfenstein 3D, all weapons are using the same kind of ammo and are progressively stronger, but unlike it, you don't necessarily discard the rest of your weapons when you pick the strongest one. The weakest pistol can be ideal to preserve ammo in some cases as it doesn't use it, while the chaingun (or its equivalent, anyway) can be used to shoot at turrets that the grenade launcher can't hit. Other differences include the addition of an automap (very useful, especially when the game starts becoming a bit too repetitive with its environments), some strange kinds of enemies (like lightning and water elementals, alongside the aliens) and having to return back to the beginning of each stage to proceed to the next one via an elevator.
It also carries some of the annoyances of Wolfenstein 3D, like crappy strafing controls (with the extra infuriating factor that you can't use specific keys like W and S without the use of an external program, because they are hardwired in the game), a tendency to place enemies in annoying spots where they can deal a huge amount of damage (because the closer they are to you, the higher the damage they can cause) and the overall feeling that the game lasts longer than it should (it doesn't help that the last 3 episodes don't offer anything new, either in the way of environments or enemies). Also, the game's low resolution can make it pretty hard to spot turrets in the distance and the inability to look up can sometimes prove fatal when you enter a door and fail to notice the turret looming upon you. Another annoyance is the existence of bio-techs. Those scientists can sometimes be useful by offering ammo packs and coins (which can be used on food vendors to restore your health), but at other times they can be highly annoying by blocking your way and standing in front of enemies. Killing them will net you a penalty to your score, which can be frustrating for those looking to get a high score.
All in all, Blake Stone: Aliens of Gold is an OK alternative to Wolfenstein 3D, but there are better FPS games, new and old out there. Full list