Shota Yuusha no Junan 4 ~Choi Defo-shiki Adventure Game~

Everything's gone all chibi and weird!

A shota hero is led by a (bad) goddess into
the lair of a monster girl.
Treasure is promised... somewhere.
No! It's a trap!

Into the super deformed cave we go.
An ecchi ADV novel (lol)

[From DLsite English]