Ah, okay. Sorry for misunderstanding.
If you aren't even seeing the Universe Sandbox ² loading screen, then something is preventing it from launching.
First, please try verifying all files were correctly downloaded:
- Right click on the game title in your Steam Library
- Select Properties
- Select the Local Files tab
- Click “Verify Integrity of Game Cache”
If that doesn't work...
- Navigate to the Local Files tab again and click “Delete Local Game Content”
- This will completely remove the installation of the game
- Once the process is complete, right-click on Universe Sandbox ² in your Steam Library and select “Install Game…”
It's also possible anti-virus software is interfering. Please try to temporarily shut down or disable your anti-virus software. If your anti-virus has a “Game-Mode,” try enabling that before you launch Universe Sandbox ².
Here's a Steam support page with more information:
https://support.steampowered.com/kb_article.php?ref=6218-USFX-5568Let me know if it's still not working. Sorry for the trouble.