The Factorio is not free game. The linux build exist but is only distributed as xz archive. I you want install it into debian/ubuntu easy way, you need download something like https://dcdn.factorio.com/releases/factorio_alpha_x64_1.1.33.tar.xz and put it into package repo directory.
Then build package yourself using debuild -us -uc command. The result you can find as ../factorio_1.1.33_amd64.deb
There is also debian package with demo for older version of game. Download and try: http://repo.vitexsoftware.cz/pool/buster/main/f/factorio-demo/