I have come to understand that some of the very best games have mechanics which support the theme of the game in some way. For me the outstanding example of this is Ten Candles by Cavalry Games.
Ten Candles is an incredibly innovative game. It was created by Stephen Dewey, who is amazing at creating games which instil feelings in people.
About the game
The fundamental setting is this - the world is now dark. There are things in the dark and everyone is going to die. Nobody gets out of this alive. However, along the way you get to tell some amazing stories about peoples lives.
The playing environment is important, as you need a darkened room. In the middle of a table there is a fireproof pan of some kind, and arranged around that are the ten tea-light candles of the name. While the game master is telling you about the game and you are doing your initial game set up, they start lighting the candles. Those candles will be the only light in the room.
Character set up is simple, with four index cards upon which you write something. One you then pass to the person on the left, one you pass to the person on your right and two you keep. You get to record a personal message on a device at the start of the game. The cards which you have are your personal resources - your virtues, vices, hopes and fears which you can (literally) burn in order to improve your chances at lasting a little longer. I'm not misusing the word literally. You set light to the index card and drop it in that central pan and let part of your life burn away.
At the start of the game you get to roll ten dice to make things happen, and the GM has none. But each time you fail, a candle is extinguished, your dice pool is reduced by one and GM's pool increases by one. A candle goes out for any reason? It never gets re-lit. It is gone.
As the game progresses, the room gets darker, it becomes harder to achieve your aims, and death draws closer. When the group is on the final candle, failures start to mark your death and exit from the narrative. At the very end - you have all died.
Each time a candle is extinguished, you go around your circle and each person pronounces a truth about the game, whether positive or negative. When I first played we all embraced the horror of it and introduced many horrible truths to hinder us!
What I really like about it
The theme of the game is dreadful, encroaching darkness. As such the gradually diminishing light as the candles are extinguished one by one builds the sense of fear and dread as you approach the end. You can barely read the dice pips or the text on your index cards, but you dare not hold them too close to the candles for fear of accidentally putting one out!
The fact that you literally burn your resources in order to keep going a little bit longer adds to the sense of desperation and theatre in the game. The ritual truths also help bond the player characters together in the game.
These atmospheric elements make it easier for you the players to invest in and experience something of the dread which your characters are experiencing.
I also love the way that as the game plays out you can discover things about your character which were not in your mind at the outset when the game kicks off. With a good group of players it is possible to develop compelling stories together.
Stephen has done many other games, and I've had the pleasure of meeting him and he is an excellent person too. I've got no hestitation in recommending that you try out this or his other games, follow him on twitter or support him via patreon.