/ @bitblitzhq  

You can buy a copy of the game from Kinguin https://kinguin.net/?r=65e1d978ecbc2

Mod Used: Contra Version 10.0.0 Beta
https://www.moddb.com/mods/contra

I recommend installing GenPatcher to update your game and add additional tools like GenLauncher for downloading and installing mods (Use the offline version)
https://legi.cc/downloads/genpatcher/