9 tools, in alphabetical order (this isn't a ranking). Check each tool's commercial-use notes before you ship assets in a game.
| Tool | Free plan | Commercial use | API | MCP |
|---|---|---|---|---|
 Layer | Free plan | Commercial use allowed | Available | Official MCP server |
| Leonardo.Ai | Free plan | Commercial use allowed | Available | Official MCP server |
 Ludo.ai | Free plan | Commercial use allowed | Available | Official MCP server |
 PixelLab | Free plan | Commercial use allowed | Available | Official MCP server |
 Retro Diffusion | Free trial or credits only | Commercial use allowed | Available | Official MCP server |
 Runway | Free trial or credits only | Commercial use allowed | Available | Official MCP server |
 Scenario | Free plan | Commercial on paid plans only | Available | Official MCP server |
 Skybox AI (Blockade Labs) | Unverified | Commercial use unverified | Available | In preview |
 Unity AI | Free plan | Commercial use unverified | Not applicable | Official MCP server |
Generative content platform aimed at game studios: style-trained models, concept art, marketing creatives and asset variations with team workflows.
Verdict: For studios that want style-trained generation with no per-seat fees; the pricing page lists a commercial licence for all users.
General image and video generation platform with trainable custom models; usable for concept art, item icons and texture ideas.
Verdict: For general concept art and icon ideas; free-tier output can be used commercially but is public and Leonardo holds rights to it, while paid plans give you ownership.
Game ideation and asset tool: concept generation, sprites and sprite sheets, textures, plus a Unity editor plugin and API.
Verdict: For Unity devs who want ideation and 2D assets in one place; its FAQ says you own what you generate, but free-plan sprite sheets are watermarked.
AI generator for pixel art game assets: characters, 4/8-direction rotations, text- and skeleton-based sprite animations, tilesets, maps and UI elements.
Verdict: For 2D devs who need pixel-art sprites, rotations and animations; outputs are usable commercially on every plan, but its terms bar training other models on them.
Pixel-art-specific image models for sprites, tiles, tilesets and animations, plus low-poly 3D model generation with export for Godot, Unity and Unreal. Also sells an Aseprite extension.
Verdict: For pixel-art devs who want pay-per-image pricing with no subscription; the site says all output is yours for commercial use.
AI video, image and audio generation (Runway Gen-4.5 plus third-party models), usable for trailer shots, teasers and marketing material.
Verdict: For generating trailer and teaser shots; the terms don't restrict commercial use of outputs, but Runway may train on your inputs and outputs.
Production-focused generative platform for game art: train custom style models on your own assets, generate images, textures, 3D meshes, video and audio. API-first with Unity/Unreal integration.
Verdict: For studios that want custom style models trained on their own art; commercial use needs a paid plan (free output is personal/evaluation only).
Generates 360° panoramic skyboxes and environments (up to 16K and HDRI on higher tiers), with an API for in-app generation.
Verdict: For 360° skyboxes and environment backdrops; the terms say you own your assets, but commercial terms below the Business tier are unverified.
AI built into the Unity Editor: an Assistant for project questions and code, plus generators for images, textures, materials, sounds, 3D models and animations, metered in Unity Credits.
Verdict: For Unity users who want AI inside the editor, with monthly credits included on Personal, Pro and Enterprise plans; AI-output licence terms are unverified.