Hi, first of all thanks for releasing your game for Linux :-)
Regarding libssl1.0 on Ubuntu 20.04, you don't need to install it, you can simply uncompress the deb archive into the game directory and set a couple of paths.
Given this game dir layout, for example:
.
├── assets
├── libcrypto.so.1.0.0
├── libssl.so.1.0.0
├── openssl-1.0.0
│ └── engines
├── README_LINUX.txt
└── Zordak
This script will set the paths to preload local ssl version (it will also set the executable flag to the game if not present yet):
#!/bin/bash
GAME=Zordak
export OPENSSL_ENGINES=$PWD/openssl-1.0.0/engines
export LD_LIBRARY_PATH=$PWD:$LD_LIBRARY_PATH
if [ ! -x $GAME ]; then
chmod +x $GAME;
fi
./$GAME
Save it as start.sh (and set it as executable with chmod +x start.sh) and you should be good to go.
Tested on Ubuntu 20.04 today.
Best regards :-D
Edit: typos on Ubuntu release