This is an improvement hack of Sonic 1 that I've been working on for a good while now. The hack is meant to improve various things in Sonic 1 and even add brand new content. The hack is still in progress, but here's what it does so far:
- Adds a brand new fade-in effect when the Sega logo shows up before the game starts
- Fixes the horizontal centering of the title screen
- Restores the unused "Press Start Button" text on the title screen
- Puts the levels in the Level Select screen in the correct order
- Changes entering levels from the level select to where you can only press A or Start to enter a level instead of also being able to press B or C
- Ports Spindash from Sonic 2
- Fixes the infamous "Spike Bug"
- Fixes the bug where jumping next to an object can cause Sonic to do his walking animation instead of his jumping animation
- Improves Sonic's shoe sprite when using a spring
- Improves Sonic's push sensor which decreases the likely hood of Sonic getting stopped by a decently shallow slope while rolling
- Improves the rolling speed cap
- Improves Eggman's Signpost sprite to resemble the 2013 mobile version's sprite
- Fixes the 100 Point Markers bug to actually add 100 points to the score instead of just 10
- Makes boss moving coding quicker in each frame
- Fixes the bug where ducking while riding the block over the lava in Marble Zone can make you phase right through it
- Removes Caterkiller from Spring Yard Zone's Pattern Load Cues due to the enemy being unused in all 3 acts, fixing one of Roller badnik's rolling frames
- Fixes the game crashing if the camera is panned down during the end of acts 1 and 2 in Labyrinth Zone
- Fixes water waves not appearing at the left screen in Labyrinth Zone if you pause the game
- Fixes the fan physics in Star Light Zone to not push the player back if they're in debug mode
- Improves Plasma Ball target X positions in Final Zone
- Adds an invisible object at the end of Final Zone to prevent Sonic from being able to fall of the edge and die
- Ports Sonic 2 sound driver assets for better modulation effect frequency
- Fixes the PSG noise bug (1-up bug)
- Fixes the bug from the SMPS driver that can cause incorrect voice data to load in the SFX if certain conditions are met
- (In progress) Restoring the Saturns from the prototype in Marble Zone
- (In progress) Playable Tails and Knuckles
The hack also comes in different revisions so that most Sonic 1 roms should work. Revision 1 is the most recommended to use.
- Adds a brand new fade-in effect when the Sega logo shows up before the game starts
- Fixes the horizontal centering of the title screen
- Restores the unused "Press Start Button" text on the title screen
- Puts the levels in the Level Select screen in the correct order
- Changes entering levels from the level select to where you can only press A or Start to enter a level instead of also being able to press B or C
- Ports Spindash from Sonic 2
- Fixes the infamous "Spike Bug"
- Fixes the bug where jumping next to an object can cause Sonic to do his walking animation instead of his jumping animation
- Improves Sonic's shoe sprite when using a spring
- Improves Sonic's push sensor which decreases the likely hood of Sonic getting stopped by a decently shallow slope while rolling
- Improves the rolling speed cap
- Improves Eggman's Signpost sprite to resemble the 2013 mobile version's sprite
- Fixes the 100 Point Markers bug to actually add 100 points to the score instead of just 10
- Makes boss moving coding quicker in each frame
- Fixes the bug where ducking while riding the block over the lava in Marble Zone can make you phase right through it
- Removes Caterkiller from Spring Yard Zone's Pattern Load Cues due to the enemy being unused in all 3 acts, fixing one of Roller badnik's rolling frames
- Fixes the game crashing if the camera is panned down during the end of acts 1 and 2 in Labyrinth Zone
- Fixes water waves not appearing at the left screen in Labyrinth Zone if you pause the game
- Fixes the fan physics in Star Light Zone to not push the player back if they're in debug mode
- Improves Plasma Ball target X positions in Final Zone
- Adds an invisible object at the end of Final Zone to prevent Sonic from being able to fall of the edge and die
- Ports Sonic 2 sound driver assets for better modulation effect frequency
- Fixes the PSG noise bug (1-up bug)
- Fixes the bug from the SMPS driver that can cause incorrect voice data to load in the SFX if certain conditions are met
- (In progress) Restoring the Saturns from the prototype in Marble Zone
- (In progress) Playable Tails and Knuckles
The hack also comes in different revisions so that most Sonic 1 roms should work. Revision 1 is the most recommended to use.