I'll admit I haven't actually played the game yet, but this looks GOOD. Of all the RPGs I've encountered in a lifetime of gaming, in feel (though not mechanics) it reminds me more of The Fantasy Trip than anything else. In some ways it's a bit sketchy -- for example, I'm a little unclear on what some of the Statements (attributes of your character, such as "I am tough" or "I have courage") do, though when you consider that out of the 10 pages, 3 are tables (which I'm naturally fond of; I am Wintertree Software, after all!), 1 is a character sheet, and the rather nice art amounts to nearly 2 more, it's actually very impressive how much is in there. It doesn't look it on first glance, but this game is dense. I love it!
In a world where games require multiple $50 books with full-color glossy pages and more art per book than the entire RPG industry produced in 1980, a set of rules that sells for $3, (admittedly, it did also cost me 5 sheets of paper and some amount of toner) and can be understood and played in minutes rather than hours, is a welcome change. It takes me back to when RPGs just required a handful of booklets and a few weird dice, instead of needing a small cart to haul your books around, and we created our own worlds, instead of following a pre-written storyline in someone else's.
Generic Dungeon isn't for the "read the boxed text to your players" style of GM, nor for the kind of players who are always weaseling and rules-lawyering, nor the people who depend on having an official rule for every possible circumstance. It's for people who want to have fun together and need a framework to do it in. That's the kind of GM I am, and the kind of people I want to play with, so this is going to be a great game. I'll be trying it out at a convention in a couple of weeks, and I expect it to be lots of fun.
I think the biggest thing is that it's a game intended to be a game, something you do for fun (hence the popularity of dungeon crawls for decades) rather than storytelling based around a deep psychological exploration of a character. In Generic Dungeon, your character can die pretty easily, but since it's more of a playing piece in a game than a complex fictional creation in a story, you can just make another one. I think that, more than anything, is what really differentiates what the early RPGs were, and the attitudes of the early players and GMs, from the modern day "storytelling" approach. That's what so many OSR games have missed because they focus on old-school mechanics for modern-day gaming styles. Generic Dungeon gets it right.
The negatives are very few: As I said, some of it is a bit sketchy; as much as I like the artwork, I'd have traded it for more explanation of a few things. Nothing I can't fill in myself, but that's because I've been playing and GMing for decades, and even published a little game of my own once upon a time. (If you are one of the people who have the long-ago Legends & Loot with its little dice shaker, treasure it!) It could definitely use the services of a proofreader. And the format is a bit inconvenient; a version formatted for booklet printing, or even 8.5x11 printing, would be nice. But those are very minor quibbles indeed.
I don't generally write reviews anywhere because I'm reluctant to write anything but 5-star reviews, and very few games or supplements merit them. This is one of the exceptions. A good game system for less than the price of a cup of frou-frou coffee is wonderful, and this is better than just "good". Get Generic Dungeon -- you won't regret it.