I had a look and the freezing is from memory usage, it jumps from 5mb in level select to up to 900mb in the level so it's loading the assets.
Also sorry to say but these look like mobile controls and this is never going to work on a mobile device, did you test it yet? The memory usage is so high it even freezes on a PC. Mobile should be around 100mb or less ideally and yours creeps up to 600-900mb on each level.