More Mario content? Oh no! Anyways... so, you know how in Mario 1 on the NES, you bounce downwards when you destroy a brick, but hover upwards in the SNES version? Turns out the SNES behavior was possibly the intended behavior? Here's how it works.

Another sample.

So, because Sonic 2 changed the ground speed cap to be more lenient, but not the air speed cap, you can actually see this issue by just running down a hill at a fast speed and then jumping. No hacks needed to see it.

This, too...

So what happens if you remove that control lock in a faster game like Sonic 2? Yeah, not ideal...

In the Sega CD version of Sonic CD, pressing left or right while in the air applies a speed cap, but unlike Sonic 1/2/3K, the control lock for when you jump after rolling was removed. As a result, the trajectory of a rolling jump can be affected by the speed cap.

Actually, here's a visible example of this behavior in this set of pulley platforms in World 3-3!

In Super Mario Bros, objects with an upwards force have a quirk with its speed cap. If their Y speed (8.8 fixed point) goes beyond max speed + 0x80, then it gets capped to max speed - 0xFF. This behavior is possibly never visible, so here's a mod to show what it looks like.

Ever seen this weird sprite quirk with the lava and platform in Marble Zone in Sonic 1? Here's why that happens.

In the remake of Sonic 3 & Knuckles included with Sonic Origins, there is a hidden credits cheat code in the title screen.

However, due to a very specific change in the code that handles cheat inputs, as well as a flag not being set when activated, this is impossible to see under normal play.

In the Nick Arcade prototype of Sonic 2, there lies leftover scraps of a build process for an even earlier build. One of the things that can be found is an earlier version of Emerald Hill's boss.

It has only 2 hit points, no hitbox for the drill, and a weird bobbing animation.

(Part 2)

A breakdown of the differences in the peelout and spindash between the original and 2011 remake.

(Part 1)

A brief breakdown of how the peelout and spindash are charged up in the original Sega CD version of Sonic CD.

Wacky Workbench actually uses a duplicate file for Sonic's object code, modified to handle all the stage gimmicks.

However, some of the updates they made to the main file didn't get implemented in the duplicate file, such as changing the spindash charge speed from 50 to 75.