"The Plant" is an engaging game which plays off the silliness of high-tech conspiracy theories by whimsically contrasting current technology with that of a former, fictional, Eastern-Bloc country.
Players learn about this conspiracy by solving mostly-innocuous, but frequently amusing, puzzles in each of the three areas of the game, but each area also contains a challenging and ingenious puzzle which provides access to the next area of the game. The puzzles are well-implemented, but each area contains a non-interactive scene which changes the game-state to allow the set-piece puzzle to be solved, and one of these scenes isn't well-clued and could be easily missed.
Nevertheless, "The Plant" is an excellent text-adventure game, which is well-worth a player's time.
"Busted's" drug-themed subject matter allows it to play with campus-life tropes in a surreal manner, with a humorous effect. This also allows it to apply some of the more annoying conventions of old-time adventures, like hunger and sleep puzzles, to its collegiate setting in a relevant and clever way.
The result is as much a frivolous survey of university annoyances and practices as it is a homage to first-generation text-adventure games. It's enjoyable, engaging, and funny.
Play the AdvSys version if you're able to; it's much better implemented than the Z-Code version.