No surprise since one of the game's major pillars is its art style
https://twitter.com/ImperatorOfPuns/status/926451393212440576
https://www.pixiv.net/member_illust.php?mode=medium&illust_id=65225076
http://squid-killer.tumblr.com/post/165790620662/day-27-the-cup-bros-in-a-more-modern-art-style#
source unknown
https://www.pixiv.net/member_illust.php?mode=medium&illust_id=65391035
http://happyfuncandywrap.com/post/166046644974/cuphead-2017
https://twitter.com/ImperatorOfPuns/status/926451393212440576
https://www.pixiv.net/member_illust.php?mode=medium&illust_id=65225076
http://squid-killer.tumblr.com/post/165790620662/day-27-the-cup-bros-in-a-more-modern-art-style#
source unknown
https://www.pixiv.net/member_illust.php?mode=medium&illust_id=65391035
http://happyfuncandywrap.com/post/166046644974/cuphead-2017