This game was exported in Flash and, as you probably know, Flash has been discontinued. As such, I can only provide access to the source code and the .swf file at the moment.
If you happen to have an ancient computer that still runs Flash in the browser, or a copy of the Adobe Flash Standalone Player, you should be able to run the game.
At some point I may port the game to JavaScript or similar, and it’s possible that the ruffle Flash emulator will get to a point where this game will run again. Let’s see.
Jostle Bastard was made in collaboration with Unwinnable for their Playable project. It was written in Haxe, using the HaxeFlixel library. Sound effects were made in bfxr.
You can read my writing about Jostle Bastard on my blog. More importantly, you can read all kinds of stuff about the game in the documentation associated with the Playable project. Jostle Bastard was also featured on Free Indie Games, IndieGames.com, Indie Statik, Oujevipo, Rock, Paper, Shotgun, Forest Ambassador, and Kill Screen.