From HOUSE OF MYSTERY 178, Jan-Feb 1969, here's a 7-page story
"The Game", by Neal Adams.
https://comiconlinefree.com/house-of-mystery-1951/issue-178/full

Some of the dialogue is a bit amateurish, but the art is among Adams' best, and I love the concept of the story.

The Adams covers on the first 25 or so issues of HOUSE OF MYSTERY really made the series. As they also did the same for a huge ratio of the DC titles from 1968-1972.