Into the Odd is a rules-light OSR adventure game put out by Chris McDowell of Sooga Games. The most notable parts are the surreal 19th century default setting, the lack of attack rolls, the fast character creation and task resolution rules (which require you to roll under one of three stats) and the changes to how your character levels and accrues more power. There are no classes, and no spell-casting system.
There are a bunch of different versions of this game going around. There's a free one-page quickstart, a free one-page summary of the rules, there's a free eight-page version, there's a free 14-page version, there's the full 48-page version that costs $14.99, and then a bunch of versions that are basically the one or eight page version of the rules with a bunch of house rules added (plus one full-colour 35-page rewrite set in the early medieval period).
Broadly speaking, what you get with a higher page count in each version is more pregenerated content and more generators (i.e. random tables to roll on), with a few new bolt-on pieces (e.g. detachments, enterprises, monsters, traps, etc.). Because the game is so mechanically simple, it relies a lot on its style and ability to produce evocative and interesting results using the generators, rather than adding more mechanics. These generators tend to be fairly good at driving play, though it's useful to read through the Sooga Games blog for advice on playing style and some interesting mechanical ideas that haven't yet made their way into any published version of the rules (Unions / orders and oddities , in particular). Most of the generators produce plain language results rather than mechanical ones, and it's up to the referee to determine what trumps what when they conflict. It's fairly easy to plug in generators and tables from other games as a result, or to make up your own (check out this very well-done arcana generator)
Like a lot of games that rely on style but don't back it up very strongly mechanically, this is going to be the kind of game where you either "get" the style immediately, or where you don't and you flounder around looking for a mechanic to give you a hook into it (which doesn't really exist). Similarly, the best players for this are going to be the ones who typically run up against the rules, rather than ones who work best when the rules clearly explain the modes of interaction they can undertake with objects in game.
I used Into the Odd to run "Rib Shack of the Demon Prince", a Necrocarcerus module, at LozCon 2016, and it was a hit. But based on playing it, I'd mention a few changes that I'd suggest you consider:
1) Impairing an enemy's attacks is too weak as it currently stands. Try allowing impairment to reduce damage to a single point of HP / STR damage instead of 1d4. When most characters have 1d6 HP (i.e. the average starting HP is 3.5), impairment is almost always the worst option to take in combat unless you're dealing with multiple foes (even running away is better).
2) Put in lots of one-use arcana or oddities, and very few repeatable ones. Especially true if the arcana in question are portable. I found PCs leaned on their reusable arcana because the mechanical effect was laid out and predictable, which made them stand out as options compared to anything else they could do.
3) This is buried somewhere in either the G+ community, or else on the Sooga Games blog (or both), but a tough adventurer accumulates some combination of experience, prestige, and tricks / stuff, and you should have some rewards prepared that hit along all three of these kinds of incentives, instead of just one. There's not a ton of predeveloped content around managing these, so it's worth thinking through your own.
For the right crew, this game is a dream, and for the wrong one it's dull and boring without enough clearly defined options. Your best bet is to check out the free versions (either the 8 or 14 page version), give it a read through, and see whether it immediately grabs you.