What are some other text-based games similar to zork?
if there are any, where I can I play them for free?
Maybe you can try "Zombie Coming Tonight", if you got android phone. it is a text-base game. http://zct.primitiveunigame.com
There are modern day text games, and the old ones can still be purchased, such as Infocom games. http://ifdb.tads.org/