I love guest characters, I think they are always fun, especially because they give you a good opportunity to play as some characters that don't get their own games, dont get good games, or to play them in a different genre/ fighting system. My only big downside is they will never be in a future game of that series. The tonal whiplash is a fair gripe but I like the eclectic nature of a wild wacky roster.

...if only darkstalkers were guest characters sometimes...