You'll find various games and demos preinstalled, thanks to an old MacWorld Demo CD from 1997. The virtual machine is emulating a 1991 Macintosh Quadra 900 with a Motorola CPU, which Apple used before switching to the PowerPC architecture (Apple/IBM/Motorola) in the mid 1990s.
Bear in mind that this is written entirely in JavaScript, so please adjust your expectations. Macintosh.js is essentially a virtual machine that emulates a 1990's pre-PowerPC era Macintosh Quadra 900 equipped with a Motorola processor.
