Thanks for the advice. Apparently there are some issues with support, there are a lot of threads about missing indexing, and they're also silent on email. It's really discouraging. It makes me think I'll have to develop a new game and test indexing there instead, because waiting around for this to get fixed isn't sustainable.
Before you start a second game, check again. We just searched itch for warship while logged out and WARSHIP is the second result, right under another game with warships in its title. The page also has its cover set and no noindex tag, so it looks like it's back in search.
If it drops out again, the direct link keeps working the whole time, so a post in a community that fits the game still brings visitors. The pinned unofficial indexing FAQ on this board says the review queue weighs genuine traffic from outside itch. We haven't been able to measure that effect ourselves, so treat it as a maybe.