You have millions of dollars and a dev team that will follow your ever whim and faithful adapt your vision as you will it. What do you make?

I would make a role-playing game with a stylized, neon-colored aesthetic complete alternative electro-rock soundtrack. The game would be well-written and be in a Cyberpunk setting with characters color-coded and based in anthropomorphic animals.

You assemble a party of three from a group of 8-9 characters. Each one has their own defined stats and skills but are open enough to develop their stats and choose their abilities to a degree. You can swap control of them on the fly in a non-linear urbanscape setting with limited adventure elements. Each character has their own unique out-of-combat skill (lockpicking, persuasion, stealth, etc) that allows you access to sidequests, more places to explore, and branching storylines. Characters are defined in personality and background but dialogue choices fleshes them out as you choose with a morally gray conflict.

Combat is turn-based and is seamless when engaged in battle. Characters have 5 action points that fill up like the ATB system, and your speed stat, your equipped weapon and skill in it, and your abilities each had an AP cost between 1-5allowing extra strategy. Combat is difficult but is fair. Attack and elemental properties as well as initiative when starting combat can potentially give an edge.

The plot is semi-nonlinear and there are several endings based on your own morally grey choices. Characters can die and romances exist. The main character is established in motive and role in the story but can be either gender and is somewhat more open-ended when it comes to character advancement. The writing can be darkly humorous and deals with themes of bigotry, order vs chaos, the greater good, and redemption or falling from grace.

You go.