Just in case this wasn't mentioned over the SP criticisms: The multiplayer actually is a ton of fun.
Yes, it really is. Although there are only two maps available, the fact that it's a very fluid system that alternates between generic "kill all the dudes" and "do this objective while killing dudes" styles of gameplay, the level of customization that you can get through upgrades and new unlocked races makes it very rewarding.
In case you're wondering how it all works, this is basically it: You first create a character. At the beginning, you're locked into humans as the only available race, and you can choose any of the Mass Effect classes. During missions, you earn both XP and credits, XP unlock abilities as usual, while credits can be used to purchase equipment packs. There are two levels available, a recruit pack for 5k that holds 5 items, some of which may be uncommon (in the TCG sense of the word). These can be usable one-shot equipment, like Medigel shots, ammo reloads, rocket launcher ammo (Which you will fully appreciate when an Atlas appears), weapons, weapon customization items, or class/race combos. If you get a class/race combo you already have, you get bonus XP for that class.
Before going into a mission, you have the opportunity to adjust your loadouts, this uses the same mechanic that was hinted at for singleplayer where powers will recharge faster the less weight you carry around with you.