Sliced using Prusa MMU edition of Slic3r. 14 hours to print. The waste tower weighs twice as much as the pikachu - but I should have made the tower bigger, the black and red didn't purge enough.
Note that the red cheeks and the black eyes overlap on one layer. If the cheeks were shifted down just slightly, or the black eyes were shifted up just slightly, so that they don't occur on the same layer, then half of the footprint of the waste tower could be eliminated. This appears to be the only layer in the print where 3 colours occur. Otherwise it printed great, no need for supports.