Shamus was originally released by Synapse for Atari 8-bit computers in 1982. It was soon ported to the VIC-20, Commodore 64, TRS-80 Color Computer, TI-99/4A and PC (DOS). It was also re-released in cartridge format for the Atari XEGS in 1987. Much later, in 1999, a Game Boy Color port was released and eventually an iOS port as well.
Atari title screen
The goal of the game is to navigate through different rooms fighting off various robotic enemies with your electrified throwing knives while collecting various special items and keys needed to access some locations with the goal being to reach the Shadow's Lair. This is an extremely difficult game to finish as most versions have 128 rooms and you often have to backtrack in order to use a key you've collected elsewhere. The VIC-20 versions is a little easier if only for the fact that it has fewer rooms...32 instead of 128.
Atari screen
As far as I know, there haven't been any other re-releases or remakes other than the Game Boy Color and iOS versions.
Commodore 64 screen
Read more: https://www.megalextoria.com/wordpress/index.php/2017/08/10/shamus-atari-commodore-64/