This game has real potential!
1. But it's a 3 for me because of the lack of sound, or maybe it did have sound but i didn't hear any could have been a bug or the game did not have any sound at all.
The character was cute looking and the background was well designed.
2. But the move action for the fluff ball is actually a 0 for me, it was too distracting because it looked like an endless loop of just 3 frames as the fluff moved/walked, personally i hated it .
I think it would have looked much cooler if it kinda hovered over the ground like if it levitated a few pixels of the ground instead of that sad bouncy animation.
3. I think the double jump is very common , but you made it work for this game and i appreciate it .
However the major drawback on this jump is that the "stomp to kill" action just didn't work out for taking out the bugs/flies. That is because you cannot expect a player to stomp on to moving objects since this action is a vertical plunge down that is fast and when you try to execute this action when you move is really hard , it is still possible but it is actually a waste of time so you would normally just ignore it and keep moving and that results in a wasted character in the foreground, this could work as a animation in the background.
4. You could maybe make the bug move over the x axis in a forward backward (left,right) motion so that you can land easily like in Mario.This might result in more involvement in the game and a better overall experience.
5. Most importantly when the game begins the screen does not fit so there's a huge block of white space at the bottom where the Life is displayed , so when you play the game or until you make the double jumps onto the first few ledges/platforms does it actually fit the screen.
6. The checkpoint save math is not a big issue and I appreciate the fact that you took the time to think of people who would not like this feature and made a setting to disable it.
Well done on the game and Good luck further !