Installers aren't typically used on GNU/Linux (only by companies that don't understand what they're doing on that platform, actually). A simple tarball should do fine (and would make it easy for distro's to roll their own packages)
There is absolutely no way its going to be a tarbar. That would imply that we will be given the source code. Larian won't be giving out the source code. As amazing as that might be, there is a greater chance of being invited to a My Little Pony birthday party by Damien where you get bitch-slapped by the Divine himself for not bringing the cake.
Wrong and tbh it sounds like you're new to GNU/Linux. Tarballs don't necessarily contain sourcecode (a tarball is just a tar archive after all, it can contain *anything*). Java, for example is distributed as a tarball.
Linux isn't like Windows where you have to dump stuff in the registry and place dll's in system folders and all that crap, just providing an compressed version of the installed application should be enough assuming it's sanely built.
Linux has installers: .run, .deb, .rpm, .sh. Ring any bells. Deb and rpm are distro specific, and I'm hoping they won't be the only option.
Most of those are *packages* not installers and they generally use something like a tarball internally anyway. It's pretty easy to reverse engineer an rpm into a tarball (and generate an rpm from a tarball. Well, depending on how well the application is packaged in the first place)
".sh" doesn't even belong in that list as it's an extension generally reserved for shell scripts (though it is sometimes abused for binary installers, IBM likes to do this iirc)
EDIT: typos.
