Same scene, two renderers

PixiJS →

Flat top-down 2D. Fast, crisp, evenly lit. The classic space-shooter look. Ship looks the same in every direction.

three.js →

Lit & tilted 2.5D. The star casts real light; the camera is angled for depth. Fly around the sun and watch the shading move.

Both have the same gameplay: arrow keys to fly a ship around a star and asteroid field, camera follows you (a taste of the floating-origin idea). The only difference is how the scene is presented. Your sprites/movement stay 2D either way.