I found this video retrospective of Snapshot (1979) by HistoryGamer over on BoardGameGeek. Snapshot separates out the combat system from Traveller book one and adds Action Points and a 15mm scale grid-based movement system. It focuses on indoor combat, mainly inside the confines of spaceships. Along with the usual eclectic assortment of weapons ("The following are polearms often carried by low technology boarding parties.") it also includes what has to be one of the weirdest rules ever.
Expletive: Not properly a movement, expletive is the venting of frustration and anger when a character is not capable of using his action points efficiently. In addition to its use in the pick-up maneuver, expletive may be used while waiting for sliding doors to open, or as desired. Expletive requires the expenditure of 1 AP per execution; it does not require triple cost payment in order to maintain a sneaking posture.