I just ran a spellcheck on Project Quintessence part 1, and even not counting the few lines of non-English dialogue and the character names, there were ten times as many real words it didn’t recognize as there were spelling errors.
Here’s a partial list. For things like religions and sexual identities, saying that labels people call themselves by aren’t words is both an example of and could contribute to “invisible minority” issues. (Unless it was done on purpose; in that case it would be directly insulting. But I’m assuming no real word was thought of and then still intentionally left out.)
Words I think it’s especially unbelievable that it didn’t recognize are in bold, and words that WordPress doesn’t recognize either are in italics.
Common words and slang:
uh
bath
plushie
anime
karaoke
nonstandard
noninvasive
ma’am
ex-wife
forth (as in “back and”)
internet
teleport
poly
Just a few of the many compound words it wants to uncompound (to be fair, “uncompound”might actually be one I just made up):
badass
chainsaw
webcomic
keychain
crossdressing
LGBT related:
bi
homophobia
intersex
Kinsey (as in “Kinsey scale”)
pansexual
Religious terms:
Wiccan
handfasting
Agni
Scientific terms:
hadron
Higgs (as in “Higgs boson)
boson
most constellation names
Weapons:
ballista
arbalest
nunchaku
On the Edge of Enlightenment 