GameBoy was the most successful console, handheld or regular, that was ever made.
Over 200 million of them have been sold (if you include all the versions of GameBoy, GameBoy Pocket, GameBoy Color, GameBoy Advance and GameBoy Advance SP)!
Although by our standards it has horrible screen quality, limited sound capability and really bad hardware even when it came out in 1989, it was still an amazing device and totally defined handheld gaming.
In the day if you wanted to make a game for it, you had to use GameBoy Assembler. Trust me you DO NOT want to code like that!
It turns out that people are still making games for the GameBoy! What really? Yes. There are several ways to do it, but one is using a C library called GameBoy Development Kit.
In this Learning Guide you will actually work through the process of making a real game on a GameBoy that can be played on real GameBoy hardware (or a simulator).
NOTE:
to make your own images and scroll background, you will need to have access to a Windows OS.
The software only runs on Windows to make image background tiles. You can follow along with this tutorial and use the provided images and I have a few Windows laptops if you want to borrow one.
We will be using a web GameBoy simulator to test our game.
If you place the web page in "inspect" mode, you can make the size be an iPhone SE and then reload.
This way you can get the GameBoy controls.
You can also use the keyboard (the controls will then disappear) as follows:
← : the left arrow key or A
↑ : the up arrow key or W
→ : the right arrow key or D
↓ : the down arrow key or S
Ⓐ : J or Z
Ⓑ : K or X
START : ENTER
SELECT : SHIFT
here is the link
here is the link