I only new about CupHead which I watched gameplay videos, I won Flint Hook in a giveaway but it's still in my Back Log I go through slowly. Haven't heard about the rest.

About Butcher... it seemed too dark for me (tagged GORE in steam page) until I saw some screenshots of the gameplay now, well... I'll stick to Flint Hook... haha :')

All in all, great list and better than the lists I would come up with (I'll probably put some uninspired $1.9 game because those what I considered true retro-styled.) Included this in my Daily Picks.