Japan has some messed up and great gaming book covers, Part 1

Yep, it's mostly Cthulhu, because CoC took over Japan at some point.

ゴミ means trash. This is a scenario collection for Shirgomi-taku, which is short for ”シリ”アスできない”ゴミ”, which means trash that you can't take seriously. It's a spin off of CoC-type play where weird and happy ends are more the norm than the doom and gloom of serious CoC.

Spielberg? I think these are the same people
that made the 30 minute dungeon RPG
 I have around here, waiting to be translated...

Happy doge is on a book titled Hound of Tindalos. Good boy, you find those right angles. This scenario is described as a heartful scenario for two, and you can buy the PDF for a mere 100 yen.

クトゥルフ神話２４時
A Cthulhu adventure with gorillas. Love the san loss.
I have another one by the same group lying around...

This one made the list because of the contrast between the honobono (heartwarming junk) and background stalker-thulu

This one is just cool and up my alley.
Title is "Let's Go to the Dungeon! II"
Which is a Dungeons & Dragons fanfic,
according to the cover.
ダンジョンへ行こう！Ⅱ

Too-Cthu! Tenguy vs Tengu.
Not the worst tengu art I've ever seen;
that honor goes to Judges Guild.
クトゥすぎ！

ウォーハンマー　　キャラクター設定の作りこみ方七選び
Seven choices to set up your... WARHAMMER?! character. Mate...