A game in C++ to learn about concurrency
Make all major changes to a new branch, and then open a pull request from that branch to master.
Need SFML 2.4.2 Download all the required packages for Ubuntu from http://ftp.sjtu.edu.cn/ubuntu/pool/universe/libs/libsfml/ and install via dpkg, since 2.4.2 is not available via the official repo on Ubuntu 16.04 and below.