UI Designer & Texture Artist for Mobile Puzzle Game (Isometric Maze/Music Game) — Unity

I'm developing Echopath, an isometric 3D maze game for iOS (Unity) where players tilt their phone to roll a ball through a procedurally generated maze, collecting notes that unlock layers of a song — the music builds as you play, and completing a maze plays the full track. The game is FULLY BUILT AND PLAYABLE (gameplay video below). All UI screens exist and function with placeholder styling. I need a designer to give it a real visual identity. IMPORTANT: I'm not asking you to build screens — I implement in Unity myself. I need a design system I can apply across the game, plus a few key screens designed in full. TECHNICAL CONSTRAINTS - Portrait orientation only. Design at 1080 x 2340 (iPhone, 9:19.5). Must respect iOS safe areas (Dynamic Island, home indicator). - Reserved gameplay colors — these are a gameplay language, not decoration: red = hazard, cyan = timed hazard, gold = collectible. Theme palettes need to stay clear of those hues. - Themes are data-driven and will keep growing — the system needs to hold up across moods I haven't built yet. - Text renders in TextMeshPro (Unity). A font recommendation with a commercial-use license is welcome. DELIVERABLES 1. Design system / style guide — color palette (working around the reserved colors above), type scale, button styles (normal / pressed / locked-disabled), slider and toggle styles, panel and overlay treatments, and iconography (pause/menu, back, lock, streak). This is the core deliverable: it's what I apply to the screens I've built. 2. Key screens designed in full: - Gameplay HUD — run timer, collectibles counter ("3/5"), menu button, and a single-line contextual prompt. Must stay unobtrusive over a moving 3D maze. - Song select and difficulty select — two related screens: a generated list of songs, then a difficulty picker showing best scores and locked states. They can share a layout language. - Level complete — score breakdown, "new best" and "new skin unlocked" celebration states, and three action buttons. 3. App icon — full size set for App Store submission. 4. App Store screenshots — a set sized to Apple's current requirements at submission time, composed from gameplay captures I provide. Additional screens I'll build myself using your system (listed so the components exist): settings (audio + tilt sensitivity sliders), ball skin select with locked/unlocked/equipped states, daily challenge panel with a streak counter, and an opaque in-game pause overlay. STYLE DIRECTION Clean, modern, minimal — calm/ambient mobile puzzle games (Alto's Odyssey, Monument Valley) rather than skeuomorphic or hyper-casual. Music-forward mood. FORMAT Layered source files (Figma preferred, PSD fine) plus exported PNGs / sprite sheets, Unity-import ready. MILESTONES This will run as two milestones so we can check fit early: 1. Design system + Gameplay HUD 2. Song select, difficulty select, level complete, app icon, App Store screenshots GAMEPLAY VIDEO: https://youtu.be/1wlZh-ZzTOY TO APPLY Please answer the screening questions — I read every response.