Pieter,

Congrats on starting your project. You're infected, and surely there won't be just one game. Love the updates and photos here. I actually enjoyed the DE simpsons playfield layout, so its a good candidate for some tweaking/a custom project.

On one of my custom games, I used those WS2812 LEDs in the exact way you're using them (I think even the same model). The main thing is being very careful about routing around coils and high EMI, otherwise you'll notice corruption in the LED data stream when you fire coils or run motors. For a first project, shouldn't matter much, just a heads up.

If you're programming it based on an Arduino, I can only offer some tips from the many projects that I've had to consult on where people have tried this:
1. Count in milliseconds (microseconds if you have to).
2. Watchdog watchdog watchdog (or you'll have components melting off of your board).
3. Single wound or double wound coils, get the PWM frequency right on the former. Never turn anything "ON" and hold it
4. Use interrupts wherever possible to maintain tight timing intervals
5. Optos are really just LEDs themselves, so apply appropriate current limiting hardware (I've seen company after company do really stupid things to mess this up)
6. POWER CHARGING/FILTERING - Flippers need a lot of current available for the initial flip. Charging caps and a decent 48V supply will help you immensely here. Otherwise your flippers will likely perform like poop, and nobody likes poopy flippers.

A switch matrix is also a valuable thing to learn, though many just go direct because it's simpler.

I've done most of my games on the Multimorphic system, and that's what a ton of manufacturers use. The good news is you can drop some of their hardware in piecemeal if you're wanting to dab with your own microcontroller runtime environment (it's all pretty much serial).

Once you fire that first coil, light the first lamp and detect that first switch hit, you probably won't come out of your house for quite some time (Which I guess is a good thing in our current situation).

Looking forward to updates!
-- Jimmy