Your game needs art, models and sound. Here are the AI tools built for that, with prices from their own pricing pages.
2D art and sprites
Scenario
50 free credits a day. Starter $15/mo, Pro $45/mo, Max $75/mo (annual billing is 33% cheaper). Paid plans include a full commercial license. Try Scenario
Ludo.ai
Game ideas, concepts and assets. Indie $15/mo, Pro $35/mo, Studio $300/mo, all billed annually. Try Ludo.ai
PixelLab
Pixel-art sprites, rotations, animations and tilesets. price: checking (its pricing page didn't show plan prices when we checked). Visit PixelLab
3D models
Meshy (from $20) and Tripo (Pro $20/mo billed annually) both have free plans with different licenses. Full comparison: Meshy vs Tripo.
Sound effects, music and voices
ElevenLabs
Sound effects, voices and music on one credit pool. Free: 10k credits/mo. Starter $6/mo (adds a commercial license), Creator $22/mo, Pro $99/mo. Try ElevenLabs