Fastest with effect

 Players = :()
 RunService = :()
 TweenService = :()
 UserInputService = :()
 SoundService = :()

 player = Players.LocalPlayer
 character = player.Character  player.CharacterAdded:()
 humanoid = character:()
 root = character:()


 leftFoot = character:()
 rightFoot = character:()


 BASE_MAX_SPEED = 
 BASE_ACCEL = 
 BASE_FRICTION = 
 FRICTION_SCALE = 
 TURN_SMOOTHNESS = 
 ROTATE_SPEED = 


 BOOST_MULTIPLIER = 
 BOOST_ACCEL_MULTIPLIER = 
 BOOST_COOLDOWN =  


 MAX_SPEED = BASE_MAX_SPEED
 ACCELERATION = BASE_ACCEL
 currentSpeed = 
 moveVector = .(,,)
 canBoost = 
 cooldownActive = 


humanoid.WalkSpeed = 
humanoid.AutoRotate = 


 screenGui = .(, player:())

 boostButton = .()
boostButton.Size = .(, , , )
boostButton.Position = .(, -, , ) 
boostButton.BackgroundColor3 = .(,,)
boostButton.TextColor3 = .(,,)
boostButton.TextScaled = 
boostButton.Text = 
boostButton.BackgroundTransparency =  
boostButton.Parent = screenGui


 corner = .()
corner.CornerRadius = .(, ) 
corner.Parent = boostButton


 cooldownBar = .()
cooldownBar.Size = .(,,,)
cooldownBar.Position = .(, -, , )
cooldownBar.BackgroundColor3 = .(,,)
cooldownBar.BorderSizePixel = 
cooldownBar.Visible = 
cooldownBar.Parent = screenGui

 barFill = .()
barFill.Size = .(,,,)
barFill.BackgroundColor3 = .(, , ) 
barFill.BorderSizePixel = 
barFill.Parent = cooldownBar

 timerLabel = .()
timerLabel.Size = .(,,,)
timerLabel.Position = .(, -, , )
timerLabel.BackgroundTransparency = 
timerLabel.TextColor3 = .(,,)
timerLabel.TextScaled = 
timerLabel.Text = 
timerLabel.Visible = 
timerLabel.Parent = screenGui


  ()
	boostButton.Visible = 
	 tween = TweenService:(
		boostButton,
		TweenInfo.(, .EasingStyle.Quad, .EasingDirection.Out),
		{Position = .(, -, , ), BackgroundTransparency = }
	)
	tween:()


  ()
	 tween = TweenService:(
		boostButton,
		TweenInfo.(, .EasingStyle.Quad, .EasingDirection.In),
		{Position = .(, -, , ), BackgroundTransparency = }
	)
	tween:()
	tween.Completed:(()
		boostButton.Visible = 
	)



 flash = .()
flash.Size = .(,,,)
flash.BackgroundColor3 = .(, , )
flash.BackgroundTransparency = 
flash.ZIndex = 
flash.Parent = screenGui


 boostSound = .()
boostSound.SoundId =  
boostSound.Volume = 
boostSound.Parent = SoundService

  ()
	flash.BackgroundTransparency = 
	 tween = TweenService:(
		flash,
		TweenInfo.(, .EasingStyle.Quad, .EasingDirection.Out),
		{BackgroundTransparency = }
	)
	tween:()



  ()
	  canBoost  cooldownActive   
	canBoost = 
	cooldownActive = 
	()

	
	MAX_SPEED = BASE_MAX_SPEED * BOOST_MULTIPLIER
	ACCELERATION = BASE_ACCEL * BOOST_ACCEL_MULTIPLIER

	
	boostSound:()
	()

	
	cooldownBar.Visible = 
	timerLabel.Visible = 
	barFill.Size = .(,,,)

	 cooldownTime = BOOST_COOLDOWN
	 startTime = ()

	.(()
		 () - startTime < cooldownTime 
			 remaining = .(cooldownTime - (() - startTime))
			timerLabel.Text = (remaining)..
			barFill.Size = .((cooldownTime - (() - startTime)) / cooldownTime, , , )
			RunService.RenderStepped:()
		

		
		timerLabel.Visible = 
		cooldownBar.Visible = 

		canBoost = 
		cooldownActive = 
		()
	)


boostButton.MouseButton1Click:(activateBoost)
UserInputService.InputBegan:((input, gp)
	 gp   
	 input.KeyCode == .KeyCode.B 
		()
	
)


  ()
	 particle = .()
	particle.Name = 
	particle.Texture =   
	particle.LightEmission = 
	particle.Color = ColorSequence.(.(, , ), .(, , ))
	particle.Rate = 
	particle.Lifetime = NumberRange.(, )
	particle.Speed = NumberRange.(, )
	particle.Rotation = NumberRange.(, )
	particle.RotSpeed = NumberRange.(-, )
	particle.Size = NumberSequence.({NumberSequenceKeypoint.(, ), NumberSequenceKeypoint.(, )})
	particle.Transparency = NumberSequence.({NumberSequenceKeypoint.(, ), NumberSequenceKeypoint.(, )})
	particle.LockedToPart = 
	particle.EmissionDirection = .NormalId.Bottom
	 particle



 leftFoot  rightFoot 
	 leftParticle = ()
	leftParticle.Parent = leftFoot
	 rightParticle = ()
	rightParticle.Parent = rightFoot

	
	 fallbackParticle = ()
	fallbackParticle.Parent = root



RunService.RenderStepped:((dt)
	 inputDir = humanoid.MoveDirection

	 inputDir.Magnitude >  
		
		currentSpeed = .(currentSpeed + ACCELERATION * dt, MAX_SPEED)
		moveVector = moveVector:(inputDir.Unit, TURN_SMOOTHNESS * dt).Unit
	
		
		MAX_SPEED = BASE_MAX_SPEED
		ACCELERATION = BASE_ACCEL

		
		 dynamicFriction = BASE_FRICTION + (currentSpeed / FRICTION_SCALE) * 
		currentSpeed = .(currentSpeed - dynamicFriction * dt, )
	

	
	 currentSpeed >   moveVector.Magnitude >  
		root.AssemblyLinearVelocity = .(
			moveVector.X * currentSpeed,
			root.AssemblyLinearVelocity.Y,
			moveVector.Z * currentSpeed
		)

		
		 lookDir = .(moveVector.X, , moveVector.Z).Unit
		 targetCFrame = .(root.Position, root.Position + lookDir)
		root.CFrame = root.CFrame:(targetCFrame, ROTATE_SPEED * dt)
	
		
		root.AssemblyLinearVelocity = .(
			,
			root.AssemblyLinearVelocity.Y,
			
		)
	
)


()