The author of this package apparently doesn't know how to pack a .deb file correctly. Not only does it not install, the paths to the executable in the various script files are wrong.
This is going to take me awhile to get this thing to work, I don't have time at this moment to work on it.
Note: The proper path to create a .deb package installer file;
All files must have a project named directory, the second directory to be created inside that project name is, "DEBIAN". Inside the "DEBIAN" directory you need all of these files included the packed archives;
control, control.tar.gz, data.tar.gz, debian.binary and md5sums
Then from the top level (just outside your project name directory). Use 'dpkg --build YourProjectDirectoryGoesHere. I'd recommend using double quotes around your project directory, that way, if you have spaces or some other weird character that UNIX / Linux does normally like or are case sensitive with go through without a hitch.
Now, I've built the .deb just fine, however, you don't have script to reslove the 'mono-complete' in your installation script.
If you attempt to install it, you run into unmet dependencies.
To fix this you need to run;
sudo apt -f install
That will get what is needed and then the dpkg with finish doing it's thing.
However, there is another problem, "scellix" should have a symlink created to go from the "Launch" button in itch to the systems directory it's located in via "/usr/lib".
I hate to say this, the tool isn't ready for use on Debian and Ubuntu. While the pictures and videoes on said package look amazing, well, there is still a lot of work to be done.