[feature(s) request] add zen mode and palette swap on a timer

[junguler]

first of all thanks for this amazing project, i'm having a lot of fun with it, i want two features added to it tho:

zen mode: this mode would be very similar to the marathon mode but with one key change, you can't lose the match, when you hit the top the game just restarts and you keep going

palette swap timer: this would be a very nice thing to have on marathon/zen mode, i really like how the pieces change colors when a new level is reached but i think it would be visually cooler to see it more often