Gustav's Lemmings

Gustav Mausenhoff, a deranged Norwegian tenor, has promised the burghers of Baltershoffen to eliminate their lemmings problem by driving out all the lemmings. Will Gustav prevail over the small squeaky powers of darkness?
Jam year: 
2017
Diversifiers: 
Lost library card
Virtuoso
Platforms: 
Web standard (HTML5, Java, JavaScript, Flash)
Technology Notes: 
NodeJS, JQuery, github.com/drom/fourier, wikimedia commons
Game Stills: