Legend of Grimrock is a first person RPG dungeon crawler reminescent of old school RPG of the same genre. It takes what was good of those old games while taking almost nothing of the bad, clunky stuff in the process.
The story is kept really short: 4 criminals (your party) are brought by soldiers at the top of Mount Grimrock and sent to die in its dungeon. They fall into a huge pit that leads to the first level of the maze itself, and they can't go back. And that's basically it for the story. I mean sure, there is some kind of plot - for example there's a guy that talks in your sleep that is trying to help you get out, and there are some documents around the dungeon that fill in some details about the place - but you don't really care about it and the game doesn't really make you care for it. It's absolutely not the main focus of the game and it's perfectly fine in my opinion. This is a game that is mostly played for the gameplay aspect and the adventure.
At the start of the game you can create your party of characters (with a good amount of options for stats and abilities, and even different races) or take premade ones, but whichever you choose everyone starts the same. No equipment, not even some clothing: you have to find things as you go through the maze. There's also some kind of survival mechanic, as you need to keep your characters fed with the food that you find in the dungeon, but it's not that big of a deal really.
The combat is pretty straightforward: you just click the weapons that your character has in possession in one of his hands, then you have to wait a while to recharge its attack. But you also need to be aware of how to move in this game: you can't just stand still while you fight. You have to circle around the enemy, try to not get stuck in a corner and so on. Fights can be pretty tense, and they only get more tense as you go on through the game.
Exploration is probably my favourite part though. Each level (that is each floor that you're exploring) in the game has increasingly difficult puzzles, and they are kept smart enough and interesting throughout the adventure. It's especially fun and exciting to find secrets when you carefully explore the environment and find out that you can open a passage in a wall by pressing this hidden button and find awesome equipment for your characters. By the way, a lot of the secrets you find in this game are actually useful in some way, so finding new gear is always very exciting. You can take notes in the map if you need and, if you feel hardcore, you can draw the map yourself by choosing "old-school mode" at the start of the game.
It's easy to learn its mechanics, but hard enough in general so it keeps you on your toes while you crawl in this maze full of monsters, traps, treasures and secrets. The scaling of difficulty is pretty well crafted, as is the level design and the enemy strength, and nothing is ever too hard for your party of four.
What I did not like, though, is that the levels in the dungeons are quite weak in the variety department, so things could feel a bit repetitive after the first few levels. You kinda always see the same textures and scenarios over and over, albeit some exceptions in a couple of levels. Also, there are almost no bosses, or not many that you can call a boss, and I felt that it would've been a cool thing to add, so that's a bit disappointing. The final boss is also a bit underwhelming: without spoilers, I felt like it was really dumb. The ending too, it's not that great really.
In summary, this is a rewarding and challenging experience, even if it is a bit repetitive. I still recommend it though, because there's not a lot of stuff like it.
I can't wait to play the second one. I hear it is deeper, has more environments and it's more open than the first one. So that should be really fun to see.