The Phaser Game Agent, a tool that lets developers describe games and have AI build them, has expanded its model lineup to four options, each with different strengths and credit costs. The update includes xAI's Grok 4.7, Anthropic's newly released Claude Opus 5.5, Meta's Muse Spark 1.3, and Claude Sonnet 5. Each model runs on updated tooling, including Grok Build CLI version 1.0, and every new game is built on Phaser AE v2.8.1.

Which AI Model Should You Pick for Your Game?

The choice between models depends on your priorities. Grok 4.7 requires only 4,000 credits to launch, making it the cheapest option, and it tends to take inventive routes through a brief. Claude Opus 5.5, released this week by Anthropic, costs 10,000 credits but is designed for ambitious projects with long, specific briefs where precision matters more than cost. In Phaser's first test, Opus 5.5 built a finished, playable game in about five minutes. Muse Spark 1.3 sticks closely to what you ask for and reliably ships a working game, making it ideal when your design is already pinned down. Claude Sonnet 5 remains the default option and offers the best balance of quality and cost.

• Grok 4.7: Requires 4,000 credits to launch; takes inventive routes through briefs; best for creative, exploratory projects where surprises are welcome.
• Claude Opus 5.5: Requires 10,000 credits; features a million-token context window; excels at complex games with long, specific requirements and prioritizes precision over cost.
• Muse Spark 1.3: Costs the same as version 1.2; follows instructions closely; ideal for projects where the design is finalized and you want it built exactly as described.
• Claude Sonnet 5: The default option; offers the best balance of quality and cost for users unsure which agent to choose.

What Major Engine Features Are New in Phaser AE v2.8?

The sandbox rebuild brings significant additions to the Phaser engine itself. The biggest addition is a full set of tools for card games with 3D rendering. Cards are real bendable sheets that curl as you lift them, bow as they land, and cast curled shadows. The front and back are one object, so flipping a card is a single action rather than swapping two sprites. There are nine dealing methods: arc, slide, flick, cascade, swirl, snap, pyramid, scatter, and explode. Cards in flight don't pass through each other or the deck.

Beyond card mechanics, Phaser AE v2.8 includes a complete solitaire game foundation that agents can build on rather than write from scratch. Options include Klondike (draw one or draw three), FreeCell, and Spider with one, two, or four suits. The solitaire template comes with drag-and-drop, click-to-auto-move, highlights on legal moves, undo, redo, hints, auto-collect at the end, and an orbitable camera around the table. This lets agents focus their effort on unique elements like theme, art, and custom rules instead of re-deriving card placement logic.

How to Use New Surface Effects and Visual Tools

• Holo effect: Creates an iridescent foil that shifts as the camera moves and the card bends, useful for rare or special cards.
• Glow effect: Produces a pulsing rim light; solitaire uses this to show where a card can legally move.
• Dissolve effect: Makes the mesh burn away with a hot, charring edge, ideal for defeated cards or destroyed objects.
• Fire effect: Displays flames climbing the face and scorching it, useful for damage or destruction sequences.
• Shine effect: A bar of light sweeps across the surface, adding polish to card reveals or transitions.
• Gild effect: Turns artwork to metal leaf under raking light, perfect for treasure or premium items.
• Ripple effect: Bends artwork under traveling waves, useful for water, magic, or distortion effects.
• Frost effect: Cracked ice with facets that glint as it turns, ideal for cold or frozen themes.

All eight effects require WebGPU, a modern graphics API. On older WebGL2 fallback systems, cards draw flat and effects are skipped, but the game still works. This ensures broad compatibility without sacrificing visual quality for modern browsers.

The engine also fixed subtle bugs that don't show up in screenshots. Moving sideways in 3D requires determining which direction is "right," and there are two answers that differ only by a sign. The wrong choice swaps left and right controls. Phaser now names all six directions (forward, backward, left, right, up, and down) so agents don't have to work them out. Similarly, mouse look had the same sign problem; a camera that tilts up when you pull the mouse down looks fine in a screenshot but is unplayable. First-person games now get built-in mouse look that handles pointer lock, sensitivity, and up-down limits correctly.

Additional improvements include vector shapes clearing away when a scene changes so title screens don't leave artwork behind in gameplay, vector trails now visible by default, and fully documented voxel editor options. The agent's engine documentation was also rewritten to be shorter and presented in tables, with every option and default listed.

What Happened to Previous Models?

Kimi K3 has been removed from the model picker. However, games already built with Kimi K3 remain unaffected; they still open, still play, and users can still ask the agent to modify them. This ensures backward compatibility while streamlining the active model lineup.

The sandbox rebuild means every agent now runs on the newest version of its tooling. This includes the release of Claude Code that Opus 5.5 requires, ensuring all models have access to current capabilities. Every game started from the update date forward runs on the new sandbox and engine version, while games already made keep the model and engine version they were built with.