Laughter is indicative of a lot of things, Akira. People can be angry when they laugh, nervous laughter isn't uncommon, and it's even present when people are fearful or crying. It's simply an expelling of emotion.

[Goro takes his hand and helps him up, because he's not an asshole, though he doesn't let go or move away so quickly this time, smirking slightly.]

Mine, however, was because I thought your impatience and lack of foresight hilarious. And oddly charming.

[So something like happiness, maybe, but mostly because Akira's stupid. He lets go after that, turning to survey their next conquest. Swings? Stargazing?]