Shovel Knight: Treasure Trove is on sale for $19.99 (normally $24.99, 20% off) on the Wii U and Switch. Treasure Trove includes the original game, plus Plague of Shadows, Specter of Torment, and the upcoming King of Cards expansions. The expansions are truly new experiences, and basically whole new games. Specter of Torment is especially good.
Sale ends 10/31
Switch
https://www.nintendo.co
Wii U
https://www.nintendo.co
3DS
https://www.nintendo.co
Specter of Torment is also on sale by it’s self for $7.99, but I would recommend buying the Treasure Trove.