return {
    'concrete',
    'deepwater',
    'deepwater-green',
    'dirt-1',
    'dirt-2',
    'dirt-3',
    'dirt-4',
    'dirt-5',
    'dirt-6',
    'dirt-7',
    'dry-dirt',
    'grass-1',
    'grass-2',
    'grass-3',
    'grass-4',
    'hazard-concrete-left',
    'hazard-concrete-right',
    'lab-dark-1',
    'lab-dark-2',
    'lab-white',
    'out-of-map',
    'red-desert-0',
    'red-desert-1',
    'red-desert-2',
    'red-desert-3',
    'refined-concrete',
    'refined-hazard-concrete-left',
    'refined-hazard-concrete-right',
    'sand-1',
    'sand-2',
    'sand-3',
    'stone-path',
    'tutorial-grid',
    'water',
    'water-green',
    'water-mud',
    'water-shallow'
}
