Commander Keen in Keen Dreams released on Nintendo Switch today, which wouldn't be of much interest to us, if it weren't for that fact that it's prompted series co-creator Tom Hall to jump on reddit. Hall, who developed the game alongside John Carmack and John Romero, had some interesting things to say about efforts to develop new Keen games since the series' last instalment in 2001.
In comments left on this thread, Hall chimes in to say that he'd "love to do a new Keen" but that he doesn't have the rights. The rights lay in the hands of id Software and its parent company Zenimax. "Every letter to them has gotten a form letter response," Hall said, when asked whether he had any contacts.
Interestingly, when asked whether John Romero has "any pull with them," Hall replies that he and Brenda Romero had "tried one year" but that they also received a form letter response.
Hall did attempt to fund a 2D platformer creation tool called Worlds of Wander back in 2013, which would have come bundled with a "spiritual successor" to Commander Keen, but it didn't reach its target.
It's interesting to hear that efforts have been made to revive Commander Keen. And as an aside, Commander Keen in Keen Dreams is a bit of an anomaly for the series: it's not currently owned by id / Zenimax, and while it did appear on Steam several years ago under a different publisher, it's since been removed. It was a somewhat obscure stopgap between the original Keen and Commander Keen in Goodbye, Galaxy. You can buy it for $10 on the Switch, or get it for free on Android.
Here's some footage: