Iron Snout doesn't launch

**Game information**
[Iron Snout
](https://store.steampowered.com/app/424280/Iron_Snout/)
**Distribution name and version where applicable**
Linux Mint 20.3 64-bit Cinnamon Edition

**Flatpak info**

flatpak --version
Flatpak 1.12.2
flatpak --gl-drivers

**Problem description**
The game Iron Snout fails to launch.

**Does this issue reproduce with native Steam**
No: the game runs fine using the Deb version of Steam
[Steam Flatpak Iron Snout terminal log.txt](https://github.com/flathub/com.valvesoftware.Steam/files/8356212/Steam.Flatpak.Iron.Snout.terminal.log.txt)
.