[ With as much time as 2B put into assessing the power, Minato was building up high expectations. But. ]

Those aren't feelings.

[ It's that bracket text thoughts he's interested in! But at least he doesn't sound too disappointed- amused, maybe, because this is something very familiar. ]

You're underestimating your help, though. I couldn't have done it without you. So, "we built something" would be more accurate.