Dungeons of Dredmor
"He fought like a sacrifice."
Exploration and combat are both kept simple. Movement through the game's procedurally-generated mazes is turn-based, so you make your choices and then the dungeon follows suit, while dealing out damage sees you switching between a standard attack with equipped weapons and whatever you've got mapped to your right mouse click. This could be a skill attack, a thrown weapon like a knife or bolo, a bolt from your crossbow, or even a potion or mushroom or piece of cheese (Dredmor's dungeons are overflowing with cheese).
It's very easy to swap items in and out of your second slot, while there's a pleasant tactical element to combat as enemies crowd around you, attacking en masse. If you're smart, in other words, you'll spend a lot of time fighting in narrow corridors with a weather eye on your back.
Enemies, meanwhile, are both brutal and ridiculous, ranging from floating genies to scissor-handed robots and rotting vegetables. If you're after that one special game that allows you to murder the Loch Ness Monster with a baseball, good news: you've found it, and while Dredmor will kill you easily and kill you often - odds are unfairly tilted in the dungeon's favour, as they should be in any good roguelike - much of the motivation to head back into the slaughter comes not from the loot you'll pick up but from the new weirdoes you might get to smack over the head with it. Now and then, in fact, you'll open a door and find yourself facing off against something the game calls a Monster Zoo: a room stacked full of giggling, high-colour death dealers. In such cases, I suggest you shut the door again.
Loot, meanwhile, is varied and imaginative, but since you can't see it on your character once you've equipped it, its charms are almost exclusively restricted to the numbers that come attached to it. There's nothing wrong with Gaslamp's handling of these numbers, incidentally - although they're split across an array of amusingly distinct attributes, which can make them slightly hard to get to grips with at first - but, while I'm complaining, it would be nice to see an update that made comparing what you've currently got equipped to what you're thinking of equipping a little easier. (Also a font size increase would be nice, as I'm old.)
These are tiny issues, however, when balanced against the complexity of what Gaslamp has created and the compact space it's fitted it all into. From the procedural gobbledegook of your character epitaphs and goon chatter to achievements that come littered with references to Indiana Jones and Kubrick, this is feelgood RPG gaming at its most authentic. It's mean-spirited, dizzyingly deep, and snarkily nostalgic all at once - and those are just the skills and attributes I look for in a roguelike.