Sonic the Hedgehog (16-bit)/Bugs
From Sonic Retro
Contents
General bugs
Missing Press Start on Title Screen
The text "Press Start" was meant to be displayed on the title screen. Due to RAM not being properly cleared after the two previous screens it does not appear. The byte that should call for it to appear is shared with the previous screens and since the RAM in this area is not reset the value is stuck in a no call state. For a more technical explanation check the Sonic Retro forums here.Not fixed in any version
Hidden Points Bug
At the end of the level when jumping to collect the hidden points the game only rewards 10 points for the 100 point flags. A explanation how to fix the bug on your own is available here.
Not fixed in any version
Level bugs
Teleport through walls in Scrap Brain Zone
On the first act find the ledges that move right then left. Go to the far right side of the wall and wait for the platform to move to the right. As soon as it starts to move right, duck. You'll go through the wall. While here, press Left to teleport right and Right to teleport to the left.
Not fixed in any version
Speed Tunnel Scrolling in Green Hill Zone
On the first act there is a series of two speed tunnels with a star post in the middle. Occasionally, if Sonic is moving too fast the screen won't scroll down fast enough and when Sonic touches the bottom of the screen he will die, as if it were a pit.
??? in ???
Fall off level in Final Zone
It is possible to fall off the edge of the level after defeating Eggman. This is only possible if Eggman is hit one final time when trying to escape. If not, Sonic's forward movement will be stopped when jumping near the edge.
??? in ???
Final Zone Boss bug
In Final Zone, getting the final hit on Robotnik early in the round will allow a player to hit him again while the piston slowly retracts. This action loops his hit counter from 0 to 255, and interrupts the defeat sequence, making Robotnik restart his attack pattern. The only thing that can be done at this point is to fight on until Time Over or allow yourself to be killed and restart the stage.
Not fixed in any version
Player bugs
Jumping next to solid objects
In certain circumstances, but most often when next to a solid object, jumping will use the wrong animation, so that Sonic appears to "walk" in mid-air. This happens often in Marble Zone while on the blocks that float on the lava. This also happens in Green Hill Zone Act Two, at the second block (the one with the yellow spring on top).
Not fixed in any version