Depends on your definition of "new" and "must-have".

• Grapple Dog 75% off — momentum-based grappling hook platformer with a very funky soundtrack and Nitrome-style 2D art (spoiler: the dev was a Nitrome artist)
• Cobalt Core 25% off — deckbuilding in space! There's an actual plot with an interesting cast of characters. The board game-style positioning mechanic was what sold me on the game.
• Cassette Beasts 40% off — creature collector with an identity that isn't just "indie Pokémon". Cool worldbuilding, heartfelt story, grown-up mechanics, and imaginative monster designs that avoid the "animal + element" formula.