There is a similar post in WoS. The first question would be what is a DOS game release?
I posted Prince of Persia (was bundled with modern PoP games), but perhaps it may not count as a release (is a re-release). Also, there are some programmers/publishers that sells games by mail (physical releases with floppies, boxes and printed manuals).
Maybe the question was what was the last DOS game released for sale in stores?
I have traveled across the universe and through the years to find Her.
Sometimes going all the way is just a start...
I'm selling some stuff!