It should be a-short-hike-windows-latest.zip - your operating system may have added the -1 if you have a prior download in the same folder.
The actual game is AShortHike.exe.
Unity announced a security vulnerability not too long ago (https://unity.com/security/sept-2025-01/remediation) and perhaps Unity games were marked as suspicious? I already patched the game to fix the vulnerability last week (the uploaded version is Version 1.10.1_patched) so it shouldn't be a problem though.