As something to compare to, I picked a random repository from what GitHub Explore showed, clicked on the first that looked like a desktop application (https://github.com/siyuan-note/siyuan/releases/tag/v3.5.4), and their Windows binary is currently 166MB for a "privacy-first, self-hosted, fully open source personal knowledge management software".

I'd claim 80MB for an entire game engine + editor for said engine is very good.