How many copies did Modern Arena sell?

198 to 322 copies, based on its 8 Steam reviews. This is a labeled estimate from the review count, not exact sales.

How much revenue did Modern Arena make?

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

Estimated owners: ≈ 198–322; from 8 reviews (8 user reviews); Thin evidence: 8 reviews. That range swings on one or two people, so read it as a hint, not a measurement.

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 Modern Arena 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.