PC fan port of early Sonic games allows you to zoom in and out on the camera

A group of encoders has the source code for decoding Sonic the Hedgehog and its sequel from 1992 of their reputed smartphone ports from 2013. This means that these greatly improved versions of Genesis games from the early nineties were developed by Christian Whitehead use the same refurbished Retro / Star Engine as power Sonic Mania—Can now easily compile for play on new platforms, including the PlayStation Vita, the Nintendo Switch, and Windows / Mac computers.

This in itself is an interesting enough hacking / coding performance. But with a little tampering, the computer versions also let players scale the game window to random resolution, enlarging the visible playing field without scaling up the core pixel graphics of the games. As you can see from the photos and videos included in this article, this adaptation effectively zooms out the standard camera in the game to simultaneously show large chunks of a stage, giving players an exciting perspective on these classic titles.

But how?

Fill your computer screen with a playable Sonic card is not exactly as simple as dragging the corner of the game window. First, you must take a legally obtained copy of one of the 2013 Sonic games (still available on Google Play and the iOS App Store) and extract the “RSDK” file to your computer (this handy video tutorial can help you here). From there, you can run the pre-compiled version of Windows and modify the settings file to expand the playing field horizontally relatively easily (you can also edit the pixel scale if you want to effectively zoom the camera’s game on a large monitor again).

Unfortunately, the game’s vertical height remains hard-coded at 240 pixels, which means the game looks like a long thin strip when extended across the width of a modern computer monitor. To expand the playing field vertically, you need to dive into the decompiled source code, change “SCREEN_YSIZE” in the retroengine.hpp, and then compile a new executable version (there are some difficult dependencies to make it work ; many thanks to @ CodeNameGamma for her help in my efforts).

The thousand foot view

However, once you get things done, the effect of this “zoomed out” view is immediately noticeable. The standard 32×48 pixel Sonic sprite becomes a small, Where is Waldoclean spot on a 2560×1440 monitor (or even smaller if you have a 4K or widescreen display). With the new perspective, players can see beyond the cramped 320×224 screen area they are accustomed to on the Genesis, allowing them to take advantage of the scale and design of these massive levels at the same time. Hidden paths and secrets that once flew past in a blur become immediately apparent when you can see a stage recording at an ultra-high level.

These 2013 mobile ports were originally designed to work on a “full screen” solution on a variety of smartphones, and the engine handles all this recalculation on its own. Enemies, moving platforms, and animated background elements generally work, even if Sonic has thousands of pixels in the opposite corner of the screen. The physics in the game still work as expected, and everything is also rendered with perfect pixel authenticity at 60 frames per second (assuming your machine can handle all the pixels in these extended resolutions).

After all, there are some weird game and visual artifacts when you try to design a game that was originally designed for a standard definition TV from the ’90s to modern computer solutions. This is most evident at the end of many levels, where Sonic can get stuck on a newly obstructive invisible wall and the game hits an infinite loop, waiting for him to run off the screen. On flat surfaces, the background tiles and even the level architecture itself can sometimes be repeated in a vertical pattern. And the AI ​​for dr. Robotnik’s boss fight also tends to freak out a bit thanks to the new, much larger playing field.

These issues can be ironed out as hackers continue to source code and build new versions of these newly decompiled games. In the meantime, however, we will never look at classic Sonic again in the same way.

List by Sega