- Perfect Overlays for RG35XX Plus/H/SP/2024
→ New GBA border option added 2026-03-04 - Game Boy Bivert
- Game Boy Metallics Overlays
- Other Overlays
- 720x720 Overlays
Perfect Overlays for RG35XX Plus/H/SP/2024
(and other 640x480 devices)
Settings with step-by-step instructions for muOS are included in the readmes in the various zip files.
These are adaptations of 1playerinsertcoin's Perfect DMG-EX, GBC, and GBA Miyoo Mini overlays.
The versions hosted here have had minor alignment fixes for the RG35XX Plus/H/SP/2024 series of devices and have been tested on an RG35XX Plus using muOS. These overlays may work on other 640x480 devices and CFWs, though ymmv with regard to setup and alignment (since all three of the devices that I'm familiar with have minor scaling and positioning differences). Russ at Retro Game Corps has put together an excellent guide to overlays and shaders on retro handheld devices that you may find useful if you're looking to get these working on another platform, or really just in general.
For the original RG35XX, see my Garlic OS repository.
For the Miyoo Mini (Plus), see 1playerinsertcoin's original Reddit posts. It's worth checking out all of their other overlays, too.
Update 2026-03-04:
- I've added a new border option based on my 720x720 GBA overlay
- See the Perfect GBA section below for details
Update 2025-04-04:
- Perfect Overlays are now included in muOS by default
- However, the updated version of Retroarch in Pixie and Goose has additional Viewport Anchor Bias parameters in Video > Scaling. These settings are not included in the README that was merged, but must be set to properly align the GBA viewport
- If you're trying to use the Perfect GBA overlay and the top is cutoff, try setting Viewport Anchor Bias to 1.00 (or 0.00 if that doesn't work, but 1.00 seems to be the solution)
- If your Viewport Anchor Bias settings won't save with your override, try deleting all existing GBA content directory and/or core overrides and saving a new override
- Updated GBA scaling settings in the README included in files on this Github page for muOS 2502.0 Pixie
The Perfect_Overlays_for_muOS zip file is a compilation of all three system-specific zip files (DMG/GBP, GBC, and GBA). Note that this file does not contain the new Perfect GBA border option added 2026-03-04. See the Perfect GBA section below for details and download links for the new overlay.
No grid, no shadow, and no grid + no shadow options are available for all borders.
Border options:
This option has a better foil effect and a more subdued shadow than the original versions. I'll likely revise how these overlays are collected some time in the future, but for now I've provided the new overlays in separate zip files. There are four options, each of which includes Perfect GBA, Perfect GBA bright, and no grid overlays, all with and without shadows (6 overlays per zip file). See below for descriptions of the options you can use to select the best version for your device.
Perfect GBA New
Perfect GBA New Centered
Perfect GBA New for Dim Screens
Perfect GBA New for Dim Screens Centered
The GBA logo on the overlays in the non-centered versions is offset toward the bottom of the screen to take advantage of black bezels. It makes for a more even look, as opposed to having the logo crammed toward the top of the border; however, the offset looks odd on devices without black bezels. For example:
On a device with a black bezel (ignore the banding; it's exacerbated by scaling and compression issues):
Compared with a device with a gray bezel:
(Note that this is an original RG35XX running Garlic OS. The border width and rendered GBA resolution are slightly different, but the same principle applies.)
The only difference between the regular version and the version for dim screens (e.g., RG35XX Plus/H/SP/2024) is that the brightness of the logo on the grid overlays has been reduced in the regular version. I expect that most people will want to play at maximum brightness when using the grids, and I find the logo ends up too bright to the point of being distracting. Whereas I haven't found this to be an issue on the RG35XX Plus.
No grid, no shadow, and no grid + no shadow options are available for all borders.
Border options:
Since I'm too paranoid of messing up to bivert my Game Boy Pocket, I thought I would make an overlay instead. This overlay works in combination with a custom palette and has an orange-purple gradient effect to help simulate more realistic lighting. The zip file includes versions both with and without the power light.
Click for installation and settings
- Download GB_Bivert_640x480.zip.
- Copy the contents of the overlays folder to your retroarch > overlays folder.
- Copy the palettes folder (containing default.pal) to your BIOS folder (/mnt/mmc/MUOS/bios/ for a 1 SD installation; this may be different for Goose). Note that this will overwrite any custom palettes you are currently using, so make sure to rename or back them up if you don't want to lose them.
Quick Menu > Core Options:
GB Colorization > Custom
Manage Core Options > Save Content Directory Options
Quick Menu > On-Screen Overlay
Display Overlay > ON
Overlay Preset...
> Navigate to retroarch > overlays > mugwomp93 and select GB_bivert_640x480 or GB_bivert_640x480_nolight
Overlay Opacity > 1.00
Main Menu > Settings > Video > Scaling
Main Menu > Settings > Video > Scaling
Integer Scale > ON
Integer Scale Axis > Y
Integer Scale Scaling > Underscale
Aspect Ratio > Core Provided
Viewport Anchor Bias X > 0.50
Viewport Anchor Bias Y > 0.50
Bilinear Filtering > OFF
Crop Overscan > OFF
Quick Menu > Overrides > Save Content Directory Overrides
- The colors aren't intended to be 100% true to real life. Consider them "inspired by" instead of accurate representations.
These overlays are identical to the ones found in my Garlic OS repository
This is the culmination of a couple of projects I've wanted to work on for a while: revisiting my first attempts at integer-scale Game Boy overlays and seeing if I could improve the default Game Boy palettes in Retroarch for my RG35XX Plus (which I've never been happy with - the screen is dark and colors are washed out). These overlays are the result. They use colored grids to tweak the appearances of the internal Gambatte Game Boy palettes.
The final versions were a compromise of color, grid line visibility, and contrast within the constraints of the existing internal palettes (e.g., changing the overlay opacity affects also affects the color and contrast). As a result, I ended up creating some optional custom palettes to help improve the contrast and in some cases (DMG, GBL) further refine the color schemes.
Note that these are likely oversaturated on better screens
The screenshots used in the pictures above were taken on an RG35XX Plus and edited to match (at least as closely as possible) what I see on my original RG35XX. The colors on my RG35XX Plus are similar if slightly more washed out. Given the difficulties in conveying accurate colors (my display isn't calibrated, your display likely isn't calibrated, your handheld likely doesn't display accurate colors anyway, etc.), it's difficult to say whether the colors you see are representative of what these overlays and palettes will look like on your device; however, each image is internally consistent with the colors on my RG35XX, so you can likely compare the raw palette images with what those palettes look like on your device to get an idea of how the overlays will look.
If you just want the four overlays featured in the images, you can download my preferred pack. Otherwise, I've uploaded all combinations of the borders x overlay grids, with and without power lights, as well as borders-only and no-borders versions, here. You'll need to download the custom palette(s) from the relevant subfolders if you decide to download individual overlays, or you can download a zip file with all of them here (make sure to read the readme for instructions).
Recommended settings and instructions for the custom palettes can be found in the readme files in both the preferred pack zip file and the top-level Game Boy Metallics folder.
- Neo Geo Pocket Color
An integer-scale NGPC overlay that uses a repeated 3x3 pixel section of 1playerinsertcoin's Perfect GBA overlay to create an lcd effect
I've created a new repository of 720x720 overlays that I'm working on. There's an integer-scale GB Advance overlay, non-integer scale grid+borders versions for GB Pocket/GB Light, GB Color, and Game Gear, and a variety of integer and non-integer scale, grid-only overlays created by 1playerinsertcoin for GB Advance, GB Color, Game Gear, Neo Geo Pocket Color, and PICO-8.
Note that Github scaling often creates banding in pictures of overlay grids depending on viewing size, zoom, etc. For best viewing, I recommend downloading the example images instead of viewing in Github.
