Sandbox Hero is a platformer with a built-in level editor. This game allows you to share your levels and play on other people's levels while making your character level up and earn coins. It was created by John Cooney, Jimp, and Anthony Pecorella.
You can move around with the arrow keys or WASD. The goal is to reach the checkered flag while dodging enemies and collecting coins. You can fight enemies with Z or K and dash forward with X or L. When you finish a level, how fast you finished and how many monsters you fought will determine how much experience you gain. Leveling up increases your health points, attack power, running speed, jumping height, and how many times you can jump in the air. You can also use a Kongpanion and buy equipment to boost your stats.
Sandbox Hero forum on Kongregate