I'm sorry I have to say this but I've tried playing webgl and get my map to work and it doesn't seem to work the only way you can play are the example levels hopefully one day Johnster will support custom levels on webgl
Here’s the tutorial from principal gaming on android go to android/data/com.johnsterspacegamesbaldifunnewschoolplusultimateedition/files/floorcustomizer and the custom floor is need to extracted (but if you need zarchiver good luck) paste on floor customizer and done!
