It follows the traditional 4koma with non-canon meetings between characters from both universes.
The first few comics have mostly .hack//Games humor, but the majority explore the idea of inserting Kite and his friends into the .hack//G.U. storyline. Most of the humor comes from Kite's altered personality or the exaggerated personalities of other characters, mainly Atoli.
(Source: dothack.wikia)
Background
.hack//4-koma was published in English by Tokyopop on May 30, 2010.