"Grab your weapon of choice, polish your Rogue senses, and get ready to be thrown into the dark and oppressing dungeons of Claustrophobia! Experience deep character development, fast-paced tactical combat, and mountains of epic loot. Here begins a roguelike quest for glory, slaughter, and anything shiny!
Claustrophobia: The Downward Struggle is a Tactical RPG Roguelike, most heavily inspired by the combination of procedural gear and enemy generation found in games such as Diablo and Torchlight, with traditional Roguelike features found in games such as NetHack and Dungeon Crawl Stone Soup. Gameplay revolves around a classless, stat and gear-based progression system, procedural dungeon exploration, and unforgiving tactical combat."

Alpha 1.0.4 changelog:
Highlights
- Added Dynamic Leveling: Enemies will no longer scale 1:1 with the player's level - instead, scaling is based on the amount of sources of experience per floor.
- XP scaling is now exponential.
Gameplay
- Added Dynamic Leveling: Enemies will no longer scale 1:1 with the player's level - instead, scaling is based on the amount of sources of experience per floor.
- Likewise, undiscovered enemies will no longer scale up when they are below the player's current level.
- Preparations made for upcoming new content.
Music
- Added the final mix of Light6.
Enemies
- Added Modifier: Illusionist
- Greatly increased Elite, Champion, and Hellish enemies Health.
- XP from defeating Elite, Champion, and Hellish enemies increased to co-inside with new balancing.
- Enemies now have increased Hit Rate at greater levels.
Stats
- XP scaling is now exponential.
- Hit Rating and Defence Rating now suffer Diminishing Returns.
- Altered scaling of Diminished values, such as Critical Chance, Armour Efficiency, etc.
- Combat Efficiency and Dual Wielding now suffer Diminishing Returns.
Bug fixes
- Fixed a major bug causing a number of Skills (including Rat-at-tack) to deal damage based on user Health rather than the intended Stat.
- Fixed a bug causing Diminished values to scale beyond their maximum values at high levels.
- Fixed a crash caused by attempting to rebind NumKey0 while at the main menu.
- Fixed Health, Mana, and Damage Multipliers on enemies.
- Fixed incorrect values on the Tooltip for Dual Wielding.

If you like the game, support the developer, buy it!     
http://store.steampowered.com/app/269590/

As of now (15.10.2014), you can get it in this bundle:    
http://www.bundlestars.com/all-bundles/immortal-bundle/

Read some guides:     
http://claustrophobiagame.wikia.com/wiki/Main_Page