A tip for those not aware: In regards to growing your bubble, ants are worth a little more than the crums and the oils spots.
I did some quick investigating with the MAME debugger and this is true. From what I can tell, your bubble always starts at the same size and always has to grow to the same size to get the mouth. If you assign values to the size of the bubble and the amounts by which it grows or shrinks for cleaning/colliding it look something like this:
Base value for size:
0Minimum size needed for mouth:
+1536Crumbs:
+45Grease:
+60Ants:
+70Cleaning Lady:
+128 alone and +the combined value of objects she has swept upKilling a roach with the broom:
+256Colliding with brush/sponge:
-256It also appears that some of the value assigned to size will carry over into the next sink, but your starting size on the next sink can only be between 0 and 255. The bonus points at the end of the sink are based on how many multiples of 256 your bubble has grown beyond the 1536 needed for the mouth.
This kind of stuff is probably impossible to count on-the-fly, but it highlights two important things for me: 1) Grab as much as junk as you can early so it doesn't go down the drain. 2) Make sure you grab the Cleaning Lady before she disappears, otherwise she takes the size-growing junk (and points) with her.
EDIT: Determined that killing roaches also adds to bubble size, and added the value to the above list. Also I suck at hexadecimal.
