Closing the initial setup with `Alt+F4` bypasses the setup process and allows the user to continue without ever specifying an install directory.
The install path is then `null`, which causes countless problems within the launcher:
- Displays `[LAUNCH]` with no status messages, and with no game directory, this will cause a crash.
- Updating the game installs it to the root of the drive (`C:\` or `/`)
- Many parsing errors from trying to use `null` instead of a valid path.
Clicking the `x` causes the launcher to exit normally.
High priority (instead of release blocker) because this only effects non-Steam users (the launcher is not publicly released outside of Steam yet), and because there is a fairly low chance of this happening in the wild anyway.