This is a example of how you can create a platformer game using C++ and SDL2 I hope this project is usefull.
opengameart.org and itch.io
clembod
https://clembod.itch.io/warrior-free-animation-set
Jetrel
https://opengameart.org/content/castle-platformer
remaxim - vergine tutto amore:
https://opengameart.org/content/durante-vergine-tutto-amore
SkyRae