So if you want it, don't hold off much longer.
"This month is your last chance to pick up Sega's arcade-ported shoot-'em-up Afterburner Climax on the Xbox 360 and PlayStation 3. Digital storefront monitor lifelower reports that the Xbox Live Arcade and PlayStation Network versions of After Burner Climax will be permanently delisted on December 24."
http://www.joystiq.com/2014/12/11/after-burner-climax-faces-xbla-psn-delisting-this-month/
So it will join Outrun Online Arcade and Sega Rally Online Arcade (Which apparently can at least still be found via a download voucher for the 360 version that was bundled with an accessory) in disappearing forever.
For those that haven't already, I'd recommend grabbing Daytona USA HD if you want it. The International Speedway Corp. licensing for the Daytona USA branding is likely running short as well and there's no guarantee that there will be advance warning or that you will see it even if there is.