I eventually both rung the bell and won with 0 death during a same run (my highscore for (deathless then) 100% is 3:19.861, which might not be that good given I didn't think of dashing instead of walking), after I thought I could never do it because I hadn't understood how dashing more than once worked and so the first part of the optional challenge always took me 100 tries until I passed it by chance, then when I finally figured it out I did a couple of more runs and managed to. The difficulty is perfect for a 0 death challenge and the game is fun, I should check your bigger games at some point.