Very fun game and congrats on the idea. Watching kenney's free asset myself i think you did a great job. Like others players have said bucket and instruction falling can ruin the run but you choose in my opinion the right amount of time and every thing that can happen bug and other problem are toO frustrating because the player didn't invest to much time in a run.
I've finished all 3 levels and it was the right amount of challenge. I think that in order to make another step of difficulty you would have to change some thing. Again congrats!