Sonic Re;Velocity

Overview

Sonic Re;Velocity is a 2D Sonic fan game with a heavy focus on high-speed momentum and stupidly fast platforming, with a unique control style and a strange emphasis on going as fast as hedgehogly possible.

Sonic Re;Velocity started life as an earlier project, known as Green Hill Zone Simulator, a joke Sonic fan game built for the RAGE 2024 Sonic Fan Games HQ event.

Sonic Re;Velocity is built in Godot Engine v4.2 and is free software under the GNU General Public License 3.0, or, at your option, any later version.

Versions

Sonic Re;Velocity's major versions are organised into "revolutions" - for example, versions v1.x.x are part of the "1st Revolution", versions v2.x.x are part of the "2nd Revolution", etc.

• 0th Revolution (SAGE 2024 Demo) - The initial version of Sonic Re;Velocity, created specifically for the Sonic Amateur Games Expo event in 2024. Includes the Quick Spin and Velocity State, but is limited to one short test level.
  • v0.1.0 - The initial version released to SAGE 2024.
  • v0.1.1 - Fixes an issue with high FPS counts by capping the FPS to 60 and properly tying the Velocity System to _physics_process. The actual game executable doesn't include the v0.1.1 version string, because I forgot.

Techniques

Wall Jump

Wall jumping is a holdover from Green Hill Zone Simulator, where Sonic can rebound and kick off a wall that's wall jumpable (in GHZSim it was any wall, but SR;V it's only jumpable walls) and send himself in the opposite direction, potentially preventing him from losing any speed.

Quick Spin

The Quick Spin is a simple yet powerful technique, where Sonic briefly curls up into a ball and performs a lightning-fast Spin Dash, boosting his speed or outright changing his direction.

To perform the Quick Spin, simply press the Spin button (B on an Xbox controller) while pressing a movement direction. A full list of the different Quick Spin variations can be seen in the move list below.

Velocity Gauge & Velocity State

The Velocity Gauge is the gauge with the word "VELOCITY" on the top left of the game window, underneath the Speed Gauge. It goes up as Sonic runs and continuously goes down over time. When the Velocity Gauge is full, Sonic enters Velocity State, granting him:

• 250% velocity accumulation
• Uncapped running speed
• Boosted jump height

If at any time Sonic stops moving, the Velocity Gauge will go down and he'll lose the Velocity State.

Controls

Tip

This is assuming you're using an Xbox controller, and Sonic is facing right. Button prompts in Sonic Re;Velocity will automatically adapt to your controller type and the direction Sonic's facing. But just in case:

• If Sonic's facing left, not right, swap ← and →.
  
• If you're on keyboard, replace A and B with Z and X.
  
• If you're using a PlayStation controller, replace A and B with ⨉ and ○.
  
• If you're using a Nintendo controller, swap A and B.

• Movement - ← or →
  • Sonic can move left and right, gradually building up speed. The screen will zoom out when he starts running, and even more when he's at Mach speed.
  • At Mach speed, Sonic will run extremely fast. In this state, it's crucial to control his speed or he'll probably fall off a ledge or crash into a wall.
  • When running or at Mach speed, Sonic will begin to charge energy in the Velocity Gauge. When the gauge is full, it triggers Velocity State, which breaks his speed limit and grants him uncapped running speed. He'll also accumulate speed much faster.
• Jump - A while on the ground
  • Sonic can jump, granting him height. Jumping off an upward slope will let him jump higher and further.
  • Sonic's jump height will be boosted by 250 units when in Velocity State.
• Wall Jump - A while wallbound
  • While Sonic is wallbound (touching a jumpable wall and not touching the floor), he can jump off of it, sending him upward and away from the wall. Be aware the wall jump has a fixed amount of speed, and will cancel Sonic's velocity.
  • Holding ← or → against a jumpable wall will stick Sonic to that wall and inhibit any vertical movement, making it easier to line up a jump.
• Quick Spin - B/→ B
  • Sonic can perform a quick Spin Dash and immediately transition into running, boosting his speed or changing his direction.
  • Quick Spin can be performed left, right and (in the air) down.
  • Chain together Quick Spin Boosts to get to Mach speed faster.
• Quick Spin Reversal - ← B while in motion
  • Change Sonic's direction, sending him running the other way.
  • This is useful if you need to turn Sonic around quickly while maintaining Velocity State.
• Quick Spin Down - Aerial ↓ B while in motion
  • Cancel Sonic's horizontal velocity and send him straight down.
• Quick Spin Comet Aerial ↘ B while in motion
  • Send Sonic straight down without cancelling his horizontal velocity.
  • This is a good way to keep Sonic's speed going if he's flying through the air. It will always travel in a perfect diagonal path.
• Quick Spin Comet Reversal Aerial ↙ B while in motion
  • Send Sonic straight down, and change his horizontal velocity to the opposite direction.
  • Like with its non-reversal counterpart, this move will always travel in a perfect diagonal path.

Devlog

The video devlog for Sonic Re;Velocity is available on YouTube.

Testing

Green Hill Zone Simulator had a test plan, so Sonic Re;Velocity has one too.

Sonic Re;Velocity has been tested on Windows 11, Fedora Workstation 40 and Android 14.

Test Plan

• ✅ - Fully or mostly meets expectations.
• ❇️ - Partially or marginally meets expectations.
• ❎ - Does not meet expectations.
• ❔ - Untested, or testing is not possible.

Test	Expectation	Windows	Fedora	Android
Launching the game	The game displays the AeriaVelocity logo, the SAGE 2024 logo and the "Real hedgehogs use a gamepad" screen with no issues.	✅	✅	✅
Title screen	The title screen displays and correctly scales to the screen, with "PRESS START BUTTON" blinking in the middle-bottom.	✅	✅	✅
Button prompts	Correctly displays button prompts for the plugged-in controller, or for Android, displays the touch button prompts.	✅	✅	✅
Controller input	Correctly receives input without issues or with minor issues.	✅	❇️, the touchpad is recognised as a controller but this is an engine issue	✅
Xbox One S controller	Correctly receives input without issues.	✅	✅	❔
DualShock 4	Correctly receives input without issues.	✅	✅	✅
DualSense	Correctly receives input without issues.	✅	✅	✅
Touch controls	Appears properly on touch-enabled devices	❔, no touch screen	❔, no touch screen	✅
Touch input	Correctly receives input without issues.	❔, no touch screen	❔, no touch screen	✅
Sonic's movement	Sonic can run, jump, wall jump and perform Quick Spin.	✅	✅	✅
Speed Gauge	Updates concurrently with Sonic's speed.	❔	✅	✅
Velocity	The Velocity Gauge fills up and Velocity State works as expected.	❔	✅	✅
Rings	Can be collected and adds to the ring count.	❔	✅	✅
Death	Sonic falling in the pit at the start will make him respawn at the beginning.	✅	✅	✅
Goal	Sonic reaches the goal and wins.	✅	✅	✅
End-level screen	The screen is displayed and the player is given an end-level rank.	❔	✅	✅

Credits, Licence and Legal Whatevers

Sonic Re;Velocity is a project by Arsalan "Aeria" Kazmi (AeriaVelocity).

Sonic Re;Velocity is free software, under the GNU General Public License 3.0.

That basically means you can do what you want with it, but you can't make it proprietary, not even if you take all the Sonic elements out. It's also a Sonic fan game, so don't sell it either. We already saw how that turned out the last time that happened...

Special Thanks

• SEGA and Sonic Team - Created and owns the entire copyright, trademarks and patents for the Sonic the Hedgehog series.
• Sonic Mania - Provided the sprites for Sonic himself and various sound effects.
• Sonic Unleashed - Provided running sound effects, the "alert" sound effect, the boost sound effect, the goal ring sound effect, jump sound effect, etc.
• Sonic Rush - Provided the goal ring and boost sprites.
• AsuharaMoon on The Sprites Resource - Ripped the Sonic graphics from Sonic Mania.
• Techokami on The Sprites Resource - Ripped the Boost graphics from Sonic Rush.