Rescue Rover was, as I understand it, a technological marvel of its time. In researching it, I discovered some interesting gaming history tidbits, including adaptive tile refresh, the Super Mario Bros. 3 PC port that never was, and the Super Mario Bros. PC game that was (called Super Mario Bros. Special - it looks and sounds awful). The two Johns in id software invented the adaptive tile refresh technique, allowing for only changed parts of the screen to be redrawn, which was vital, given redrawing the entire screen would take multiple seconds (as opposed to miliseconds). They tried and failed to sell this tech to Nintendo, and it's worth reading a little further into the story. All of this is to say, I consider Rescue Rover a part of gaming history, and I am glad it's part of my collection.
That said, the games are pretty dated by today's standards. The EGA graphics are fine; they won't impress any of the VR crowd, but they have a pleasing, straightforward cartoon aesthetic that has aged well enough.
The problem is the lack of modern quality of life features that we would expect from such puzzle games. Most pressing is the lack of complete information. There is no way, for example, to view a puzzle in its entirety. There are also whirlpools that will teleport boxes (which you can push into water to form a bridge), but it's not always clear where they lead. There's also no rewind mechanic: you need to restart the level if you make an error. Essentially, you will need to rely on trial and error, but errors are punished. Features like these may not have been attainable in 1991, but that won't stop their absence impacting your enjoyment.
The games are also feel relatively short. The levels are fairly small, and there's only 60 of them (30 per game). The time to complete is inflated by the trial-and-error, but the price point feels a little steep. I would advise waiting for a sale.