When it comes to stealth games, no other game manages to capture the atmosphere and uniqueness of the very first Thief.
Thief isn't your typical shoot-em-up game. It requires you to use your head and find the best way to resolve the situation by alerting as little amount of guards as possible. You need to peek behind corners, sneak very slowly not to make any unwanted noise, stay in the shadows and sometimes just stop, think and inquire the environment. Do you hear a guard approaching? Would it be safe to go through here? Is there an other way to get past this area? Of course, you are offered a set of ingenious gadgets that help you get through the areas such as water arrows that can be used to douche torches, moss arrows to soften the floor so you will not make noise as you walk on it, noisemaker arrows that can be used a distraction, lockpicks to help you through locked doors and so on. Patience is definitely needed, so for hot-tempered gamers this game might not be the best choice.
The atmosphere, one of the key elements in the game's greatness, is just unmatched. The whole game takes place in a dark, medieval-sort-of city and all the missions are set at nighttime. Thief is at it's best with a good headset because the sound is absolutely terrific. Thanks to the haunting, ambient sounds in the background and the dark, gloomy setting the game is bound to give you creeps from the very first mission to the late parts of the game. Now, a lot of the criticism of the game is focused on the dungeon-exploring, undead-filled missions. I personally thought the game shined at it's brightest there, because the undead missions in the game are some of the most nerve-cracking and exciting I've ever played.
Now something about the story. The story itself in the game isn't actually anything special, but the way it's executed and narrated just fits perfectly with the game's creepy and haunting style.
The mission design is, as well, excellent. The maps are very engaging and fascinating, with loot and valuables scattered in places you wouldn't instantly know to look from. On every playthrough I manage to find something new; an area, a secret,a hidden valuable that I didn't find on my previous one. And that's why Thief is one of the games you just want to keep playing on and on again. For first timers, the game's mission design will probably seem a little inconsistent and incoherent, and your bound to get lost a couple of times in the longer missions.
To put it short, great game mechanics, haunting atmosphere, fascinating mission design, strong narrative and excellent sound make up for a game that is absolutely worth playing today. What we have here is the father of stealth genre, and a damn good one too.