Roguelikes are one way to solve the art problem. As someone else mentioned, the Unity asset store has plenty of assets too - some are free, and many others are

Roguelikes are one way to solve the art problem. As someone else mentioned, the Unity asset store has plenty of assets too - some are free, and many others are reasonably priced. There are plenty of 2D assets available, as well as 3D if that's what you're looking for. Last time I checked, the TOS/EULA says you can use Unity purchased assets outside of Unity games, too - as long as you download them through the Unity editor. So you could potentially use the art assets you buy there even if you want to write your own game engine from scratch. You might be able to find what you need here, too: https://opengameart.org/ https://opengameart.org/