Today's watch is a game watch for the movie Star Trek II Wrath of Khan.
The gane actually is a generic spaceship shooting game which was released by Nelsonic (as Space Attacker) and Majestron (as Cosmic Wars). This particular version was licenced from Paramount Pictures Corporation and branded for the 1982 film. The handheld museum site says this is made by Collins Industrial, but that is not mentioned on the watch. The back of the watch just mentions it was made in Hong Kong and by Ambassador Imports. From the things I've seen online, I think it's likely that this was released in or shortly after 1982.
It works using a two layer LCD display, with the time, and day on the top layer, and the date and game on the layer below (-the date uses the same digits as the game score).
The game is a shooting game with the launcher/gun in the middle, and three curved paths above where the targets move. The rest is pretty self-explanatory - you use the gun to take out the targets to score points! There are A and B versions of the game which change the speed depending on your skill level.
Apart from the time and game, the watch also has an alarm function and a light. It's original price was $19.95. The watch manual can be found at the Handheld Museum web site.