This is a paid asset, but now you can download Super Platformer Assets Free.
Detail this asset from Unity Store: Original Link
Super Platformer Assets v2.0
“If possible, please buy the package to support the developer”
Super Platformer Assets is the best pixel tileset for platformer, side scrolling, action, jumping, adventure and all kind of 2D mobile and web games.
– Includes all of the graphics as layered PSD and transparent PNGs
– Player: idle, run, roll, jump, fall, wall-jump, climb, bow attack animations
– Enemies: Bat, Slime, Patrolling
– Tileset: (16×16px) 40 Platform (ground) Tiles. They are pretty much all you will need. (All items are NOT in the same size! (explosion, menu buttons etc.))
– HP – Score UI, Boxes, Treasure, Bomb, Coins, Hearts.
– Moving platforms types, Ice, Fire, Mushroom, Spikes, Weak blocks.
– Ladder, Water, Flies, Torch, Long Living Grass, Rocks, Plain Grass, Grass with Flowers, Bridge. (Torch, grass, and dust animation frames are not included. These mechanics created with Construct2 plugins for the preview video.)
– The Mechanics and a test scene are NOT included. All mechanics are shown in the demo made with Construct2.