I would hire a development team to make the best videogame for the brain that's both challenging, plays at your pace, and has good aesthetics and storytelling.
I would hire the Skullgirls Animators, Lauren Faust, The guys who made Nes Battletoads, The guys who invented DnD if they are alive, The guy who made Devil Daggers, The Co-op developers on Starcraft 2 and the StarCraft/Brood War developers, Some of the guys who worked on Doom (the recent one), and the people who made Panoramical. And some random games with good sound design like Donkey Kong Country or Mario sorta sound design so it keeps people in and so the full spectrum of sound will be good all the time anyways.
I would give them each a percent of the total gains from sales plus a normal wage for the work they tend to do.
The team will be organized so you can put up ideas because those are alot of creators with alot of good ideas potentially and we need everyone to be able to speak up. Oh and I am on it too, the game has to be enjoyable and something I would actually play and I would be the one providing the theory on maximizing it for the mind.
The game would be totally aesthetic, have large variety, it recognizes the speeds at which you press which buttons and how fast/often you use new abilities and old abilities as time goes on in each game mode to try and understand your learning speed and current skills so it can provide a lightly stronger challenge each second for you to adapt to. I want it to also account for perception skills. Like theres a room of 80 objects you have 20 seconds before a bad guy blocks the door n gets you or something *subject to change or parallel or similar scenarios* and then they notice based on the brightness, where your eyes tend to linger, which items you had a preference for visually, which items you had a preference for based on description and which ones based on use.
Then it encourages you to use lesser used abilities more over time, til eventually you are doing every skill at peak level and your peak keeps rising due to muscle memory and the game having an effectively constant difficulty increase that it knows you can handle.
And each playthrough will differ because your skills will differ and based on your skills there are different aesthetics. And the story will keep you engaged with just plain enjoyable moments cuz of Faust, humor of the 'toads', badassery of doom. And then the 'toads' help to employ true skill oriented mechanical variety.
Then it has an rts trippy aspect in first person somehow. Like in missions you teleport to locations, can posses units, can spawn units of many varieties each with odd niche roles. And the game constantly changes so you need to relearn the abilities relearn what units there are and what structures, relearn enemy units, enemy unit behavior strats change based on a spectrum and 3-d graph determined on the aesthetic alterations which are determined based on your skills.
But so you do not miss out on anything it needs to be like an evergrowing spectrum that branches out so you don't miss any unique combinations if you go from 0 skill to mastered. Which means it should be independent from a difficulty calculator. And then eventually you may realize different aesthetics mean you are getting too comfortable or not comfortable enough with certain strats.
The story will be about exploring different perspectives and strategies and dealing with alternate strategies for which there is an infinite spectrum of.
And the game should be graphically simplistic enough so that more of the ram can be used for predictive difficulty on the changing system or it'll be really imbalanced, and it'd require alot of playtesting with people of various controls and skills and game histories.
It should be intellectual gameplay, whilst skill oriented gameplay (think faster/outplay oriented or tactics, And clever technical strategy or mindgames oriented etc)
And one philosophy for skill gain is, the game's speed can change throughout time. Slower to 50% all the way to faster x% based on skill level and frame-rate. Spatial distortions. Contrast changes, color variability, camouflage intensity of enemies (transparency and camo patterns)
The game should be trippy for the highest skill levels like the entire game ate 20 tabs of acid and a pound of magic shrooms and have a breathing tube on where you perpetually inhale dmt
and because you slowly improved at it over the course of 10,000 hours the game is eventually entirely unrecognizable to noobs but you from muscle memory, reflexes, and subconscious recognition skills and abstract thinking can habitually deduce everything that's going on constantly even though the enemies are shapeshifting entirely once per frame while having distortions and color changes camouflages and transparencies brightness and textures all at the same time, including the environment shifting constantly as well. Someone next to you be like 'wtf is that an indoor pool that turned into a whale and wishes it were a clown or something?' Naw man, that's a fireman I spawned.
And I would make it for VR. (lol on other consoles too of course, but on vr 10k hours in would be sadistic lol)
... And now that I think about it the second thing I would do is hire people to help with a thing to try and get psychedelics legalized because studies say they grow brain cells so can increase rate of learning like when they used it on mice. So its actually good for you. So that's where alot of my money would go to as well.
Then I would hire people to have plants genetically modified to contain all non-addictive nootropics (brain enhancers) and psychedelics, and so it has dna from weeds and grasses and cacti so it spreads like wildfire and can survive in harsh climates.
Then I would visit the world. Then provide funding for stuff to keep people young forever.
And of course find ways to make more money doing other stuff I like so I can keep doing weird ambitions with my money. Perhaps make tons of expansions for the game idea.