An empty Challenge Act Gate.
Challenge Acts are Acts that appear in Sonic Generations. They are accessed via Challenge Act Gates in the area above each stage. There are ninety Challenge Acts; each stage has five for Act 1 (Classic Sonic) and Act 2 (Modern Sonic). Completing the first Challenge Act for any area unlocks a Boss Gate Key, and completing all of an area’s challenge acts with one character will restore a bit of color to the act’s Challenge Area. In addition, any Challenge Act the player completes will cause a hanging bell to appear above the Challenge Act Gate that, when rung, will spawn a roaming musical note that unlocks a random music track or piece of concept art.
List of Challenge Acts
Green Hill
Act 1
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- The Buzz Bombers' Revenge!: Beware of Buzz Bombers! Reach the goal before time runs out.
- Knuckles: Horde of Enemies: A horde of giant enemies will try to interfere in your race with Knuckles.
- Swingset Circus: Use swings to go up and up and reach the goal in the allotted time.
- High Speed Challenge: Collect Power Sneakers to reach the goal before time runs out.
Act 2
- Look Out Below!: Reach the goal before time runs out, but watch out for the crumbling course!
- Tails: Way Past Fast: Race to the goal against Tails in his airplane.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- Jump Rush: Master the Jump Panels as you bounce your way to the goal within the time limit.
- 300% Boost Gauge Challenge: Your Boost Gauge is tripled. Reach the goal to earn the Boost Gauge Up Skill!
Chemical Plant
Act 1
- Tails: Toxic Skies: Press Triangle/Y to grab Tails' hands to fly and reach the goal within the time limit.
- Which Switch is Which?: Flip the various Switches and make your way to the goal within the time limit.
- Aqua Shield Challenge: Use Aqua Shield to reach the goal in time and obtain the Aqua Shield Skill!
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- Invincibility Challenge: Get the Invincible power-up to get past hordes of enemies and reach the goal in time.
Act 2
- One Ring Challenge: Reach the goal in time with only one Ring!
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- Amy: Taking the Leap Together!: Press Triangle/Y to call Amy for a super-high jump to get to the goal in time.
- Grappling with Grabbers: Avoid the Grabbers' immobilizing grasp and get to the goal in time.
- Underwater Ring Machine: Collect a set number of Rings scattered by the Sprinkler enemy and reach the goal in time.
Sky Sanctuary
Act 1
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- Eggrobo Rush: Reach the goal in time while fending off a bevy of menacing Eggrobos!
- Aerial Paradise: Use Warp Points to make your way to the goal in the allotted time.
- Ring Time Challenge: Use Ring Time with Triangle/Y to get a set number of Rings and reach the goal in time to earn the Ring Time Skill!
- Amy: Topsy Turvy: Race against Amy while riding on a spinning top and beat her to the goal.
Act 2
- Knuckles: Buried Treasure: Press Triangle/Y to make Knuckles dig up Medals! Collect a set number and reach the goal in time!
- 200% Boost Gauge Challenge: Your Boost Gauge is doubled. Use the Boost Gauge to reach the goal in time.
- Balloon Bonanza: Use balloons to bounce extra high as you make your way to the goal in time.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- High-Speed Hijinks: Enemies move and shoot at double speed. Get to the goal in time!
Speed Highway
Act 1
- Cream: Chao Hunt: Compete with Cream to find more Chao than her and reach the goal.
- Hot Pursuit: Avoid getting hit by the pursuing enemies and get to the goal in time.
- High Speed Challenge 2: Collect Power Sneakers to reach the goal before time runs out.
- Resisting Arrest: Beware of Cop Speeders! Reach the goal before time runs out.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
Act 2
- Overdrift: Grab as many Rings as you can while drifting and get to goal in time.
- Hot Pursuit: Chase the Sprinkler enemy that's dropping Rings. Collect a set number and reach the goal in time!
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- Drill Baby Drill: Smash your way through boxes as you descend to the goal before time runs out.
- Espio: Master of Camouflage: Only the searchlight can reveal Espio. Face him and get to goal in time.
City Escape
Act 1
- Lord of the Board: Show off your skateboard skills while racing to the goal before time runs out.
- Thunder Shield Challenge: Use the Thunder Shield to reach the goal in time and obtain the Thunder Shield Skill.
- Rouge: The Bombardier: Watch out for bombs Rouge drops and get to the goal in time.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- Rite of Spring: Springs everywhere! Use them to bounce your way to the goal in time.
Act 2
- Cream: Helping Hand: The only Rings are the ones Cream drops for you. Get to the goal in time.
- Dash Ring 1-2-3: Pass through Dash Rings in order and reach the goal before time runs out.
- Topsy-Turvy: Use the Horizontal Bars and Spinning Platforms to reach the goal before time runs out.
- High-Speed Hijinks 2: Enemies move and shoot at double speed. Try to get to the goal in time!
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
Seaside Hill
Act 1
- Rescue the Animals!: Save a set number of captured animals from Capsules and reach the goal in time.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- Espio: Way of the Ninja: Press Triangle/Y to have Espio attach a rope to the hooks and reach the goal in time.
- High-Speed Hijinks: Enemies move and shoot at double speed. Try to get to the goal in time!
- Underwater Challenge: Keep an watchful eye on the underwater terrain and get to the goal in time.
Act 2
- Rouge: The Temptress: Press Triangle/Y to have Rouge take out enemies using her wiles and reach the goal in time.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the goal.
- Trick Island: Use Rainbow Rings to pull off enough tricks and reach the goal in time.
- Surf, Sea, and Sand: Take on various course and find your way to the goal before time runs out.
- Terror From the Deep: Skim the water's surface and try not to get chomped by a Giant Chopper. Get to the goal in time!
Crisis City
Act 1
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the Goal.
- Goal Post Juggle: Don't let the Goal Post hit the ground as you get to the Goal in time.
- Vector: Through the Storm: Call for Vector Y/Triangle to get by spots you can't pass and reach the Goal in time.
- Flame Shield Challenge: Use Flame Shield to reach the Goal in time and obtain the Flame Shield Skill.
- Ring Time Challenge 2: Use Ring Time Y/Triangle and reach the Goal in time to get the Ring Time Skill.
Act 2
- Power Stomp Challenge: Use your Stomping skills to reach the Goal before time runs out and unlock the Power Stomp Skill.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the Goal.
- Switcheroo: Put your brain to the test by hitting switches to get to the Goal in time.
- Blaze: Piercing the Flames: Call Blaze Y/Triangle to get through the flames and get to the Goal in time.
- Four-way Cannon Cavalcade: Go from one Four-way Cannon to another and get to the Goal before time runs out.
Rooftop Run
Act 1
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the Goal.
- High-Rise Balloon Climb: Use the Big Balloons to climb higher and higher and reach the Goal in time.
- Dash Ring 1-2-3: Pass through all Dash Rings in order and reach the Goal before time runs out.
- Charmy: Don't Bug Me!: Watch out for Charmy! Reach the Goal in time while avoiding Charmy.
- One Ring Challenge 2: Reach the Goal in time with only one Ring!
Act 2
- Barrel Ring Bonus: Smash open barrels to get the Rings inside and grab a set number before time runs out.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the Goal.
- Rooftop Rail Grind: Go boarding across the rooftops and clear the stage in time.
- Endless Boost: Boost to the Goal before time runs out to earn the Endless Boost Skill.
- Vector: Pick Up the Beat: Pass notes back and forth with Vector until the croc misses the beat.
Planet Wisp
Act 1
- With Your Powers Combined: Use the Aqua, Thunder and Flame Shields to get to the Goal in time.
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the Goal.
- Goal Post Juggle 2: Don't let the Goal Post hit the ground as you get to the Goal in time.
- Chase After Blaze: Try to catch Blaze before time runs out, but watch out for the bombs.
- Rescue the Animals 2!: Save a set number of captured animals from Capsules while avoiding bombs dropped by Sprinklers and reach the Goal in time.
Act 2
- Doppelganger Race!: Face off against Sonic's double and beat him in a race to the Goal.
- Cart Challenge: Ride the Cart and get to the Goal safely in time.
- Charmy: High in the Sky: Press Y/Triangle to call Charmy to create a path so you can reach the Goal in time.
- Action Master: Wall Jump, Stomp, and Lightspeed Dash your way to the Goal before time runs out.
- Orange Rocket, Blast Off!: Use the Orange Wisp to turn into the Orange Rocket and reach the Goal in time.
