Just a suggestion: Maybe releasing a joystick-only version and a separate paddles/mouse-only version could be a viable way to keep all 24 levels? The homebrew Commodore Plus/4 Arkanoid port a few years ago also simply released two different versions. I’ll only buy the game once my 1351 mouse is supported. Good luck!
Challenge accepted! :) I'm happy to announce that the v1.1 update is coming later today. It includes full 1351 Mouse and Paddle support. I've spent the morning testing it on my real C64 and C128 hardware to make sure it's pixel-perfect. I even had to optimize the code to the last byte to fit the new drivers in! Get your controllers ready!
Updating later today!