I tried this distro out on a virtual machine, very well done IMO. http://crunchbang.org/about/
http://steamcommunity.com/app/221410/discussions/0/864959336480249695/ steam for linux on crunchbang :D
a more recent guide if you run into problems, http://www.huzaifah.org/2014/01/steam-on-crunchbang-11-waldorf-64-bit.html good luck
Mint comes with synaptic if it doesn't type: sudo apt-get install synaptic. get your software from there. It is just a gui front end for apt (mints/ubuntu/debian) pakagae manager.
This isn't windows you use your package manager to get new stuff, using websites may cause breakage since it may have not been tested for your distro.
If you want propriety stuff, say, Minecraft, thats fine