Aseprite is a pixel art and animation editor.
Blockbench is a low-poly 3D editor.
TIC-80 is an open-source fantasy console mimicing 8-bit systems of old. All the tools you need to make games are included.
WASM-4 is an minimalist fantasy console targeting WebAssembly. WASM-4 is bot as mature as TIC-80 but fun nonetheless.
raylib is a minimalistic game development library. Easy-to-use and just plain fun.
Scratch is a visual programming language and a set of tools for kids to learn programming and share projects.
MakeCode Arcade is a set of tools for kids to learn programming and make games.
itch.io is a game publishing platform for indie devs that has lots of creator friendly options.
The Vlambeer Toolkit is a great list of tools and talks for indie game developers.