Developer Miroslav Nemecek has created a Raspberry Pi Pico Library capable of outputting high-res video via VGA. The new project is called PicoVGA, and it's already available for you to download and tinker with.
The developer released the library just this week, and it comes pre-loaded with a series of demos. According to Nemecek, the project was designed to be user-friendly and easy to integrate with gaming. As such, there are multiple game examples on Nemecek's official YouTube channel.
PicoVGA offers four separate graphic overlay layers, each supporting transparency. It can output formats between 256x192 and 1280x960 depending on the configuration of your project. It also offers built-in image compression as well as optional PWM output for audio.
You will need eight resistors to use this library—Nemecek offers a precise wiring diagram on his website for interested parties. Demos are loaded via USB and can be controlled with a keyboard using a console program (Nemecek suggests something like begPutty).