Well, first things first: Ancient Odysseys - Treasure Awaits! can be played with or without a GM (referred to as a Director in the rules). Having read thru (yet to play) the game rules, I would say that it probably works okay without a GM, but if a group were to play more then once or twice a GM would be needed to add depth to the roleplaying experience.
Task resolution is resolved using a single d6 and adding and subtracting the appropriate modifiers.
The system is simple, as it should be for an introductory game. There are just three classes (Vocations): Warrior, Rogue and Wizard and four character races (gnome isn't one of them, so you can work that out on your own).
Character generation is simplified in that you roll randomly for one of 6 sets of predetermined ability stats based upon your class. So, random and not... kinda. Characters have 3 stats, ranging from a score of 1 to 5. Wizards will be higher ranked in Reasoning, Rogues will excel in Awareness, and Warriors will be the ones with the highest Fitness.
Choose four skills (Pursuits) for you character, roll for some armor, choose a weapon package, if a Wizard choose your spells and lastly pick your other gear (torch, rope, satchel or grimoire). They say you can be up and running in about 10 minutes... I suspect you can prepare a character in less.
Spells descriptions remind me a bit of OD&D. Short, simple and to the point.
So, overall the rules look workable. They are composed of three books: Basic Play is what is says it is, the game rules. The second book is The Dungeon. Here we find the introductory adventure, suitable for solo, group, or group with GM play. The third book, Further Adventures, give the GM information on running a game, some monster stats and a nice amount of simple but random tables too flesh out one's own dungeon designs.
The author states at the end of the book three that he was aiming for simplicity for beginners and nostalgia for veteran gamers. I definitely feel he found a decent introductory system for new players (but it would definitely work much better with an experienced GM at the helm, but then, so do all RPGs. Does it hit the nostalgia mark? Maybe if RPGs weren't so rooted in wargames... there is a lot of abstractness in the system... you are either front line or in the back of the marking order for example. The Conflict Action Map has the positions of closest, farthest, sneaking or behind. You won't be measuring squares or flanking opponents. You will get to kill things and take their stuff - success is based upon killing things and taking their stuff. Wait, I guess that does make it a RPG that hearkens back to the early days of role playing ;)
I'm going to give Ancient Odysseys a 4 beer steins out a 5. Really nice introductory RPG but long term re-playability may be lacking. This may or not be an issue, depending on your group. Some may want a deeper system, but AO does what it does very well.