It's Chex Quest with more corridors.
It's a fun and charming distraction. The randomly generated content lies primarily in the map layout, the level of weapons and armor you pick up, and which enemies you will be facing on each floor. There are some weapons with status effects, and a varity of alternative items like stims, shields, and explosives. It's just enough to allow for a bit of experimentation.
As you play more you can choose to start with different perks and items, but by floor 20, your loadout will reflect your playstyle rather than the "background" you chose to start with.
The more you play, the more intel you get, which can be spent on permanent stat upgrades, more backgrounds, and enemy strengths and data. You also unlock story logs which carry on the odd humor of the game. You can play the game fully without touching them though.
Besides each floor being made entirely of corridors and rectangle rooms with texture swaps for the walls, the big flaw with this game are some odd bugs. I haven't encountered any game breaking bugs or crashing, but sometimes you will see a few enemies who have spawned outside the map that you can't shoot, or the music will stop and not start playing until you reach the next floor, and how strange the game window acts, as it if its moved away from the screen's center, strange things happen. Screenshots suck to.
Playing the demo though shows off quite a bit of what the full games provides for only a couple of the easiest floors. It should expose any bugs that there may be on your system, or if this type of gameplay is your thing.
If you are craving Chex Quest: The Roguelike. This is the game for you. Just enough content and variety at a $5 price point that allows for cheap, quick, fast-paced, tactical gameplay. What it may lack in the variety of items you may be used to from Binding of Isaac, it's quirky humor, lively enemies, and plenty of opportunity for thoughtful experimentation, it holds its own, if you keep in mind what kind of games its drawing inspiration from, classic old-school shooters.
Like I said, it's pretty much Chex Quest with more corridors.