Superposer

Getting started

The setup assistant

The first time you open Superposer it shows a short welcome, then gets itself ready ("Getting Superposer ready"): it installs the Windows runtime, Apple's graphics translator and its Steam support from inside the app. That takes well under a minute. Copies built without these parts ask for them instead (see The Windows runtime and graphics translator).

Then Setup (in the sidebar) shows what your Mac still needs, one card per step:

  1. Superposer in Applications. Only if you opened it from the disk image or Downloads: Move to Applications moves it and reopens it from there.
  2. This Mac. Apple silicon and macOS 15 or later, checked for you. On macOS 28 or later it warns that Rosetta may not run every game yet.
  3. Rosetta. If it's missing, Copy Command gives you the one-line install, and Apple's Instructions explains it. (Opening any Intel-only app also makes macOS offer to install it.)
  4. Free space. The first install needs about 2 GB free. If there isn't room, the card says how much to free up, before anything starts.
  5. Internet connection. Shown only while you're offline, with what needs the internet.
  6. Steam. Installed, and signed in with "Remember me" so it can start games without asking. If it isn't installed, Get Steam; if you signed out, Open Steam.
  7. Windows runtime and Apple graphics translator (D3DMetal). Normally already done.
  8. Steam support and Steamworks for Windows games. Small pieces some Windows games need. Steam support is Valve's bridge between Windows games and Steam. When your copy of Superposer doesn't come with it, your Mac builds it by itself in the background from Valve's published source: a few minutes, at low priority, with a progress bar on the card, and games that don't use Steam's features can be played meanwhile. It needs Apple's free Command Line Tools: click Install Apple's Tools… once, Apple's own installer opens, and the build starts by itself when it's done. If something goes wrong the card says why in one sentence and has Try Again.
  9. Steam integration. Lets Steam install and play Windows games; see Turning on Steam integration.

Fix All does every remaining step in one go; Step by Step walks you through them. Every step shows what it will change before it changes anything, and records the change so it can be undone (Changes to your Mac). When everything is ready, Go to Library.

Want the guided tour again? Help › Superposer Tour. The welcome screen is under Help › Welcome to Superposer.