bluGill

You can maybe stretch that 4 hours to several days. However you must get enough solar in 4 hours to provide more than 1 day of use. You will probably get to 6-8 hours of production from your panels, but the production is reduced in the off hours and there are almost always a few clouds reducing your output even at peak times so until proved otherwise just count on 4 hours. (prove can be several years worth of data, or careful local climate calculation possibly with various devices to handle the sun moving)

How reliable do you need to be - https://solar.lowtechmagazine.com/ often goes offline because there wasn’t enough sun to keep their servers up - would this be acceptable for your servers? (you should spend a lot of time on that website when it is up - it will teach you more than anyone else here)

Will you allow yourself to plug in the backup if there isn’t much sun for a few days (either yourself or some automatic system) - just the ability to go 20 hours on battery and enough solar to recharge the battery in 4 hours on a sunny day would get most people to 90% solar and will be a lot cheaper than chasing to 100% solar all the time - but that might not be good enough for you.

The general rule of thumb if you never can go down is you need to be able to run for 2 weeks without any sun, and enough solar to then recharge those batteries when there is 4 hours of full sun. Of course the weather where you live makes a difference. If you live in the desert your worst possible day will always be followed by a day where you can completely recharge the battery so you need much less batteries; while those who live in arctic locations will not get any sun for a couple months and so need a lot more storage.

Contribute to some other game that already exists if possible. that is the power of open source - when many people over many years come together to work on all the tedious details to make a complex polished game free from market pressure. When you do many choices have already been made for you, so they can tell you where to start. Want to add a new puzzle, put a picture on some wall, or whatever - they will tell you how to do that.

If nothing is like your idea you can start from scratch. Likewise sometimes the existing people involved in the game are jerks and you need to start over or fork - but are you sure it is them and not you. These are not ideal cases though and should be avoided. Much better to work with others if possible.

If you start from scratch you should be thinking about what game engine to write in. You can write a game from scratch in raw code, but in general step one is picking your engine and then living with the limits of that engine.