Link: https://segaretro.org/Keio_Flying_Squadron

I was watching an unrelated video that just happened to mention that Keio Flying Squadron was (at time of filming) the most expensive Sega CD/Mega CD game there is. I must say that the title of "most expensive" belonging to a shmup makes me a little proud -- in a perverse sort of way!

The only way to play it now, as far as I can tell, is through emulation. It never appeared on any collections nor was it remastered for later consoles.

According to Wikipedia, "In July 2020, Limited Run Games CEO Josh Fairhurst stated that he tried to get a rerelease of Keio Flying Squadron going, but JVC would not do it without official blessing from Sega." On the one hand, it's a kind of a shame. On the other... LRG kind of sucks anyway.

https://en.wikipedia.org/wiki/Keio_Flying_Squadron

JVC also sent out bunny ears with copies of the game.

That might have contributed to the cost.