This is a guide for hackers. It describes how to implement air combo in SOR2 just like this hack: https://www.romhacking.net/hacks/4592/

This guide works on the original SOR2 (the US version that you can purchase on Steam). It does not work on BKII or the Syndicate Wars. However, you are encouraged to reverse engineer this guide to adapt it to BKII and SW.

You will need a hex editor and the Sega Genesis ROM checksum fixer. After you follow the steps in the guide, you should fix the checksum of the ROM.

Special thanks to Ivex, who shared his knowledge with the author.