
This Ludum Dare I worked on Scrambl’d, a fast-paced, puzzle-platformer for the Nintendo Game Boy. It is an actual Game Boy game, meaning it works on any hardware that plays ordinary Game Boy cartridges. I have played it on my original Game Boy, the Game Boy Pocket, Game Boy Light, Game Boy Color, Game Boy Advance, Game Boy Micro (through an emulator) and the Super Game Boy. It works on all of them flawlessly, but it does not look the same on either. This was something I had keep in mind while creating graphics and designing levels, and I figured I could share some of my insights with you since the topic of creating games for old handhelds seems to intrigue many (judging by the wonderful feedback we’ve received so far!)
First things first, the original Game Boy sports a 160x144 pixel screen and can display only four colours: white, light grey, dark grey, and black (or four shades of green if you will). If these two things were the only limitations, I would consider making graphics for a Game Boy game a quick, easy, and enjoyable task. But as you may already suspect there is more to it than that. But let us leave the techy stuff out for now and focus on those four shades of grey and the tiny resolution.
The first and most obvious thing you need to consider when making graphics for the Game Boy is visibility. The four colours and low-res is already a bit complicated to get around as is, but when designing with actual hardware in mind, you need to remember that the screen of the original Game Boy was very small, and it wasn’t backlit. As such, it is hard to see anything on unless light conditions were optimal and even then, you will struggle to see anything if the graphics is not tailored to help you. Long story short, you have to put more mind into making things visible and clear when working on an actual Game Boy game than if you’re working on a game with similar resolutions and palettes supposed to show on a modern type of monitor.

I focused on contrasts for this project, making sure that all interactable but stationary objects had a relatively even colouring, while the player character and interactable objects were outlined in black and with bright highlights. Stuff in the background was set to blend in even more as to not confuse the player. But things doesn’t end just there. Depending on what hardware or software is used to play a Game Boy game the visuals may vary a whole lot.

One thing we had to avoid was mixing tile and obj graphics in certain manners. See, tiles can use all four colours while the obj graphics trade one of the four for transparency and can be drawn on top of tiles. The ability to overlay tiles with obj to create more dynamic and varying visuals is tempting, and for the original Game Boy this would always render the result we wanted. But if the game was played on a Game Boy Color it would sometimes spell disaster due to the fact that obj and tile graphics are then rendered in different palettes! This is why the player, NPCs and items are different colours than the surroundings in Pokémon for example, and in the case of Probotector 2 it suddenly changes part of one character into another color, yuck! (I love Probotector, don't get me wrong.)

In the end, we did use this to our advantage however, making sure that anything animated or moving was obj and that everything stationary was made from tiles. This way, the effect of the contrast was enhanced further on some platforms, making Scrambl’d more clear and visible than before.
Hope you had a good read :) Now, go play Scrambl’d!