Some desire a proving ground - I think it's a great idea for new players to get the hang of the game, and helps somewhat limit access to those that might come on here to scribble a couple frames - not necessarily to troll but because they're wondering what happens and how game play works.
The Dustcatcher has a purpose, and I think Reed's idea with the multipliers is interesting, but for different reasons, some aren't fond of the results (being shown publicly etc).
So, here's what I'm thinking.
Using the current leveling/point system, create a grouping of levels that essentially forms a proving ground. Similar to how the unlocking is currently set for number of games one can play or create, keep levels 1-9 (just playing with numbers here) playing with each other, then a second group of 10-29, a third of 30-54, and finally 55+. Consider them groups 1-4 (for lack of a snazzy name.) Group 1 can only play group 1 started games, group 2 can only play with group 2, etc... BUT have the option to opt in to play with all groups from the one you're in or below (so a group 3 player could choose to play with groups 1&2 as well as their own).
Here's where the dustcatcher comes in.
The dustcatcher prompts are supposedly more difficult because players keep passing them over, right? So instead of offering the added points, move them up a group. Example - A group 1 started game has a prompt that no one will draw, so instead of adding a bonus to it, bump it to the group 2 players. After someone plays it, it becomes a group 2 game.If no one plays it, it continues to move up. If it reaches the top group and no one still wants to play it, then it gets the ax. I think this gives the potentially more complex prompts that the higher group players might appreciate a chance, and helps keep them from landing a scribble from someone who doesn't understand game play yet. Also, I think players would find it less frustrating if the scribble frame (or equivalent) occurred earlier in the game where it may be recovered from and end on a higher note, than when it falls at the end.