Gung-Ho is kind of an oddity. While Morishita had a really good idea for a mobile game, and had impeccable timing for releasing it, I think he's actually really bad at being a CEO.
With their vast influx of cash, Gung-Ho has bought a few deadweight studios like Grasshopper, released the same low budget, generally low quality dedicated device games they always have, and have had a very reserved title count in general in the mobile, online, and dedicated device spaces. None of these titles have been very impressively produced as well.
I don't see any signs that they're using their cash to entice high profile hitmakers or corporate managers to join their company and make new successful titles either, so it's unlikely that the quality or success rate of their new games is going to change either.
Pretty much everything they've done seems to follow in the fancy of whatever interests Morishita personally while spending as little cash as possible so they can coast indefinitely.
Comparing them to COLOPL, another huge-hit mobile company run by a notably young person, and they make serious efforts into launching as many successful games as possible. They have two top ten mega hits (in the monthly charts) and a bunch of other strong titles throughout the top 100. That's a company that will probably stick around as a notable player while Gung-Ho fades out within the next couple of years.