If you were in downtown Manhattan last evening and you didn't stop by the Mercury Lounge, then you missed out on a super-secret MGMT show.

While it was a surprise for many to learn of the secret set, the band DID drop a hint on Sunday, via their Myspace blog. You know, if you were, like, one of ten people to find their silly little flag amidst the bustle of downtown Manhattan.

Under the moniker Smirking Worm, the electro group performed a slew of MGMT favorites to a crowd of about 250, throwing in a few tracks from their upcoming Congratulations (which is slated to drop on April 13 via Columbia Records*). In addition to their Brian Eno tribute track (creatively titled "Brian Eno"), the group also treated their crowd last night to the recently-leaked "Flash Delirium" and the ten-minute dandy "Siberian Breaks". What a delight that must have been if you were able to squeeze into the tiny venue!

Watch a decent-sounding version on YouTube below. (Beware: it's a pretty darkly-lit stage, but the sound is acceptable.)

Hopefully, they'll decide to change the artwork for Congratulations, because the current selection will give Tails from Sonic the Hedgehog a run for his money. Or his lunch.