Adventure Space Alien Game Concept

I’m building an adventure-style game that centres on a mysterious space alien protagonist, and I’d like a creative partner to help shape the concept into a solid, production-ready package. The project is definitely a Game (not a film or book) and the core experience will lean toward classic Adventure mechanics—story-driven progression, exploration and clever interactions—though I’m open to weaving in touches of action or puzzle elements if they strengthen the design.

Here’s what I need from you:
• A concise Game Design Document detailing the narrative arc, key characters, setting and core gameplay loops.
• Visual mood references and rough concept art that capture the alien, the worlds they’ll visit and any signature items or technology.
• A level-by-level outline that explains player goals, challenges and rewards, making sure progression feels intuitive and engaging.
• Recommendations on engine or toolsets best suited to realising the concept, keeping scope and feasibility in mind.

I’ll provide any additional story seeds, thematic constraints or reference material once we start. If you’re passionate about imaginative sci-fi worlds and can translate ideas into clear, practical documentation, I’d love to see samples of your previous game concepts or design work.