Strawberry
A tiny 2D game engine focused on usability and simplicity. Written in Beef language, and using SDL2. To run the sample game, in the Beef IDE select Open Workspace, and select the Strawberry/SampleGame folder.
Related tools:
~Beef Language (programming language and IDE, free) https://github.com/beefytech/Beef
~Ogmo Editor 3 (level editing, free) https://ogmo-editor-3.github.io/
~Aseprite (sprite and animation editor, $20 USD) https://www.aseprite.org/