Recolouring doesn't take an awful lot of time, but shuffling everything into individual level tilesets is more difficult. I want to have a nice variety of visuals with no two levels looking the same, so each area needs specific styles i.e. pillar/wall type, platform type, ground type. It's hard not to overdo things and allocate too many different tiles out of worry that it might all look samey, but in practice, you really don't need that much to be effective.
(Music is a WIP by Arkhan, written way back for the initial Win version)
The second area has had basic mapping completed, with most of the foreground tiles in place. I'm currently placing all the background wall tiles which is a less exciting job. I've decided that it would be easier to sort out the bulk of the backgrounds and mapping before I go back to the enemies. At least then my focus is on one thing at a time.