If you would like to play the famous Transport Tycoon Deluxe open source version under Linux Mint 18.* or Ubuntu, follow these steps below.
First you will need to download the stable version of OpenTTD, and according to your architecture select either the 32 or 64 bit versions.
For Linux Mint 18.3 (64 Bit) select "Linux Ubuntu Trusty 14.04 (X86_64, 64bit)"
Once you have downloaded the game, go to this site below and download this binary package : libicu52_52.1-3ubuntu0.8_amd64.deb
Now all you need to do is to launch terminal and install the packages above.
First let's install libicu52_52.1-3ubuntu0.8_amd64.deb by typing the following command into your terminal
sudo dpkg -i libicu52_52.1-3ubuntu0.8_amd64.deb
Once it's completed, go ahead and install OpenTTD
sudo dpkg -i openttd-1.7.2-linux-ubuntu-trusty-amd64.deb
If it's completed without any error, you should be able to find OpenTTD in your Applications/Game folder.