It's been a little while since we last heard anything out of Inti Creates regarding Blaster Master Zero, and while there is still no indication that we'll see the likes of Beck from Mighty No. 9 included as a playable character, there are nonetheless still some neat new additions in a free update that's just landed today.
In addition to the Nintendo Switch version receiving triple the number of save slots and the EX Characters gaining the "call SOPHIA" ability, the biggest addition is a new Boss Blaster Mode (unlocked by beating the game) that allows you to run a gauntlet of the game's bosses one after another, putting your claim of being a Master of Blasting to the test.
What's more, the Nintendo Switch version also gets a Co-Op version of said mode. Sadly, it's only for the Boss Blaster Mode and not the main game, but now you and a friend can each choose from Jason, Gunvolt, Shantae, Shovel Knight, and Ekoro -- or pick the same character to double-up on a particular strategy -- to take on the mutant bosses that await.