What would be nice is you have a dps higher than a monster's hp then the extra damage is automatically attributed to the next monster, that way you don't need to spend so much time going through the lower levels when the monster's never have more hp then a thousandth of your dps.
Does anyone else share my sentiment that the shotgun is the best weapon in this game. You can kill multiple people while never having to worry about missing from a distance or running out of enough people to sustain a combo just when you get spree 5.
A good badge for this game would be getting a certain number of goals in endless mode without the ai getting any goals. An impossible badge for this might be getting 100 goals without the ai getting any.