How many copies did Grudge sell?

624 to 1k copies, based on its 26 Steam reviews. This is a labeled estimate from the review count, not exact sales.

How much revenue did Grudge make?

Grudge is free to play, so there is no copy-sales revenue to estimate.

A labeled estimate from the public review count (adjusted for release year), not exact sales. Owner data cross-checked with SteamSpy.

We don't have enough similar games to place Grudge in its genre yet, so these are its own numbers, not a genre read.

Sizing up your own game? See what its genre can realistically do before you build it.