This mod is a simple retexture of the default character. This mod is basically Pikachu in Qoute's clothes and does not have any impact on the normal gameplay. This mod is made for pokemon fans and is very easy to install/change in the Cave Story+ folder. This sprite will only work on normal mode...
It is the normal ending yes but there are diffrent credit pictures which show you Quote wearing the mimiga mask
Thanks for the comment Captain Fabulous
Cave Story has multiple endings but in Cave Story+ there is a secret ending you can aquire by doing these objectives down below. This special ending is known as the Mimiga Ending.
~~Mimiga Ending~~
[ ]Defeat Ballos
290 Counter
[ ]Iron Bond
[ ]Restore Curly's Memories
Booster 2.0
Drain/Reboot...