This is a paid asset, but now you can download 2D Platformer Sprites Starter Pack Free.
Detail this asset from Unity Store: Original Link
2D Platformer Sprites Starter Pack v1.1
A beautiful collection of essential platforming graphics to get you going!
The starter pack includes a character with animations (Idle, run, take damage and float – for jumping), your trusty enemy slime, basic building blocks, collectibles, containers which to hold said collectibles and more!
Fonts are not included.