Play Reaper's Crypt
An homage to the first CRPG from 1975, PLATO's The Dungeon aka DND aka PEDIT5.
Reaper's Crypt has a map randomly generated when you hit New Game, but thereafter you will continue to explore the same labyrinth, up to 20 levels deep. Somewhere in the depths is the Reaper's Soul, which you must find and return to the surface to end your eternal cycle of death and resurrection.
The rooms are drawn very abstractly, this is a game about resource management, not tactical maneuvering (my upcoming Mac game is much more about that). There'll be some more "color" to them later, though.
Your character starts with random stats (Strength, Dexterity, Constitution, & Intelligence), probably fairly weak. But you can get better! You can return to the surface (take the stairs up from level 1) to rest & convert gold to experience. When you reach 1000 experience, you will gain level 2, +1 to one stat, more Hit Points, and more Magic Points; each level after costs about twice as much.
Equipment is very important to your survival. You will find a wide range of weapons and armor. You must ready these first!
In each room, there may be one or more monsters (over 30 known types!) and you must defeat them by fighting or casting magic, or escape (based on Dex), to continue. Many monsters are immune to some attacks or have special attacks of their own.
As you explore, you have a chance to find secret doors and traps (based on your Int). Heavy dungeon doors are only opened by lockpicking (based on Dex) or bashing (based on Str), and can damage you (based on Con). Escaping from various traps depends on your stats, and they're not all deadly, just troublesome.
When you die, and you will die many times, some of your treasure will be preserved in a corner of that room; you may be able to find it again. You resurrect at the starting stairs, with one less level and some experience lost, and one stat reduced.