I just wonder what happened to this question which I asked some time ago. I was going to recall the name of the game, but apparently the question was deleted.
The question was deleted as per updated site policies, which now prohibit any form of "identify-this-game" questions. The updated policy is reflected in the site FAQ, and you can read more about why it happened by reading these meta-discussions.
In any case, your question was about Commander Keen, from the Commander Keen series of games.