D&D Gamma World in actual play

So, yesterday I participated in the Wizards of the Coast Gamma World Game Day and I have to admit, it was a blast. Sadly we didn't have a lot of players so we ended up having two tables each with a GM and three players. We were charged by he mayor of the town we were in to investigate some mysterious happenings at an old medical laboratory just outside of town. I was playing a psionic Yeti, and we also had an earth shaking cockroach and a doppleganger. Character creation in the game is quite a bit different from regular D&D 4E. Each player rolls 2d20 to generate random primary and secondary origins. Your origins determine two of your ability scores and each provides one power. Your primary origin allows you to place an 18 in one of your ability scores, while your secondary origin awards a 16 in another. after that, your remaining scores are generated by rolling 3d6 in order, which I love. I actually like that chance that I could roll a 3 for an ability, but then I'm weird. Equipment isa lot more generic than in D&D, but that makes for in some cases more interesting equipment. Weapons are grouped into light and heavy by class, (melee, ranged) and then one-handed and two handed. This means that I can have a 2 handed weapon and say that it's a huge club, while someone else can have one and say that it's a garden rake, which I think adds to the overall amusing feel of the game. Armor works in a similar way, being classed as light, medium or heavy.
My character as I said before was a psionic Yeti and my main weapon was a parking meter. Combat is very much D&D 4E, but there is no magical healing and there are no healing surges, making the game far more dangerous. To counteract this somewhat, each character is permitted to use their second wind, which is now a minor action, once per encounter. Second wind in Gamma World heals 1/2 of your total hit points. Additionally, short rests after each encounter allow for full healing.
For each encounter, every player is dealt one alpha mutation which provides some for of special ability. The player can use this card once during the encounter and then it becomes "tapped" much like a Magic the gathering card. At the end of the encounter, the mutation card are turned back in and each player draws a new one for the next encounter. When using an Alpha Mutation, players also have the option to attempt to overcharge them by rolling 10 or higher on 1d20. Successful overcharging enhances the power, while failure can lead to some hilarious side effects. I used a time shift power and failed my overcharge roll, which led to my character vanishing for 1d6 hours. Of course I rolled a 6. :-) There has been a lot of debate around this mechanic, but I for one am a huge fan of it. I love the random element and while players are allowed to build their own custom mutation decks with a minimum of 7 cards and no more than 2 of the same kind of card, I think that I prefer the wackiness of using random cards drawn from the master deck that comes with the game.
Treasures in the game fall into 2 categories, ancient junk and Omega Tech. Ancient junk isn't exactly what the name says. Some of it is junk, but some of it can be useful too. One of the players found tape, while I found a saxaphone. The treasure system sort of reminded me of the random equipment table in Aftermath. Omega Tech are the real "treasures" These are more akin to magic items in D&D and are usable once per encounter. My Yeti found a Leaky Fusion Rifle, which did 7d8+1 damage, but caused 2d8+1 damage to the user.
I have to say, I'm a big fan of this game. I'm not convinced that it would be completely viably for a long-term campaign, but o while a way a fe weeks, I think it's splendid.