One of my favourite games of all time, this was criminally under-appreciated when it was released.
The atmosphere was like nothing else I'd played before, or have played since. The soundtrack (one of my favourite OSTs of all time, by the wonderful Nathan McCree) was absolutely perfect, evoking some of Danny Elfman's score work for Tim Burton.
And that's appropriate because, visually, this game just drips that cartoonish-horror aesthetic that Burton is known for. As with the music, the visuals don't come across as an attempt to imitate Burton's work, but are clearly inspired by them.
Also worth noting, it made use of 3D polygons to create some visual affects and dramatic moments that, while nothing exciting today, were genuinely jaw-dropping at the time.
It's not a perfect game (what is?) but it is unique, and has more character than most games, both of the time and today.
Swagman is also a but tricky to getting running via emulation, and original copies (especially the Sega Saturn version) tend to go for pretty high prices.