The Amiga 500 Plus launched officially in 1992 as a minor revision to the existing A500. Primarily redesigned for cost savings in the production.
The Amiga 500 Plus also benefitted from these cost savings in two key areas. The first was that the Amiga 500 Plus shipped with 1mb as standard as well as the new kickstart 2.04 and Enhanced Chip Set (ECS). This did cause issues with some games that were designed for the original A500 hardware. This could be resolved by investing in a switching kickstart board so the user could switch back to 1.2/1.3. Alternatively, a cheaper method came later in the form of disk utilities such as Relokick, which provided a software solution to achieve the same thing.
Commodore by this time was on the path towards making bad decision after bad decision. Not long after the release of the A500+, the Amiga 600 launched in March 1992 making the A500+ the shortest-lived Amiga. This was a terrible timing since the Amiga 600 essentially replaced the now cost reduced and more profitable Amiga 500+.