You should consider using Irvue - Unsplash Wallpaper, which has much more feature and much less bugs.
Unsplash Wallpaper
Unsplash Wallpaper is a menubar application that will automatically update your wallpaper at a given interval with an image from Unsplash. Default interval is 24 hours.
Find the pre-packaged OSX version on the releases page.
Commands
npm run build
npm start
npm run publish