The AppImage allows you to distribute software/games for Linux that don't need installation of dependencies and one binary will "just work" out of the box on nearly any distro after being marked as executable. I'd love to add support for this in ENIGMA to be the default export option, although i will have to do a lot of reading up on how that format works. it appears the easiest way to do it is to convert an existing deb package, although i don't know how to automate creating deb packages, since the only way ive done it is through debreate which doesn't support automation i don't think.
It might support the BSD's as well, but I'll worry about working on that one on my own.
I don't know as much about Flatpack as hugar just brought it to my attention while writing this post. The site says all apps it creates are sandboxed and therefore we won't need to create a sandbox ourselves manually if we use this.