The game ends after the 57th level, right? When I finished it, I got stuck on an empty screen with particles.
Same for me. Bit strange that there's no definitive message that it's the end; and 57 levels is also not a number that feels conclusive. I'm playing the version that has been made available to Portmaster on some emulation handheld devices, so I really wasn't sure.
The earlier featured videos below also ends the same way though, after level 57.