This is a typing game using shoes.(shoesrb.com)
Please download a package from an official site.
http://shoesrb.com/downloads
If the *.rb file is given to the executable file of Shoes, it can be made to start from CUI.
/Applications/Shoes.app/Contents/MacOS/shoes typing.rb
However, probably, it will be better for specifying the full path of shoes one by one to set up alias, since it is time and effort.
alias shoes="/Applications/Shoes.app/Contents/MacOS/shoes"
Then, you can start only by executing the following.
shoes typeing.rb