WARNING!: The solutions to unlock this content are in Walking Spoiler territory, so everything spoiler-based is unmarked here. Please proceed with caution.
There is a variety of content to unlock throughout this mod, just like in the base game.
Levels / Hubs
- Christmas Hunt at NiGHTS
- Hint: Collect 10 Emblems
- Simply enough, you just need to locate 10 emblems throughout the game to unlock this secret. Doing so will grant you access to both the Unlockables Hub and NiGHTS Hub for the first time.
- Mario Goomba Blast
- Hint: Collect 15 Emblems
- Like with the last secret, just search for 15 emblems in the levels and hubs to unlock this level in the Unlockables Hub.
- Mario's Spring Hill Koopa Blast
- Hint: Collect 20 Emblems
- Once more, you just need to acquire 20 emblems throughout the game. This will unlock Mario Koopa Blast Zone in the Unlockables Hub, and Spring Hill (v1.01-1.04 and v1.08) in the NiGHTS Hub.
- Red Volcano v1.09.4
- Hint: Leave the volcano / Need 7 Emeralds
- This is the first of the tough v1.09.4 RedXVI secrets. Like in the original version, you need to have acquired all 7 Chaos Emeralds first. Next, you need to access GFZ1 (v1.09.4) and provoke Red by jumping three times on his house, nearest the start. He'll send you to "hell" as punishment, which is the stage in question. Escape successfully, and you can proceed to the next step of the process, with Red Volcano Zone (v1.09.4) available at any time in its Hub.
- Castle Eggman Zone (Demo 4)
- Hint: Need 7 Emeralds
- To access the part of Castle Eggman Hub that holds these levels, you need to have all seven emeralds on you, akin to the unlock condition from the original.
- Greenflower Zone (SAGE 2000)
- There is no hint to unlock this, but the switch to access these stages is in the Greenflower Hub, in the same location as its emblem.
- Deep Sea Zone 2 (SAGE 2000)
- This level can be accessed via a hidden button in Deep Sea Zone's Hub. After pressing it, the entrance will be opened. Unlike the Greenflower Zone variant, though, this won't stay open, and must be repeated to access this stage again.
- Forest Fortress
- Hint: 60 Emblems
- Like with the base game, collect 60 emblems to allow access to this level. It can be found in the same room as the v2.1 levels for Castle Eggman Zone.
- Techno Legacy + Spring Hill 2.1
- Hint: Still get 100 Emblems
- Like with the original versions, you need 100 emblems from throughout the game to unlock these levels. Once unlocked, you can find Techno Legacy with the Dev Demo 4 THZ2 and v1.0 Boss levels of Techno Hill Zone, while Spring Hill (v2.1) is present with the other levels in the NiGHTS hub.
- Neo Aerial Garden Zone (v2.0)
- Hint: Visit "Heaven"
- To get this unlock started, you first need all seven Chaos Emeralds. Go to Castle Eggman Zone 2 (any of the v2.0 variants), and a wooden gate will open for you with the emeralds, allowing you to skip the first section. Afterwards, taking an alternate route and slipping into a hidden room will let you find RedXVI, who has understood how harsh he was and had reformed, being a pope for this area. He then remarks that instead of sending people to Hell now, he'll send them to "heaven" instead. After this, you're sent to Neo Aerial Garden Zone. Once completed, you can play it again from the Unlockables Hub.
- Trying to re-enact this secret after unlocking it will trigger something new; interacting with RedXVI again will raise your ring counter to 9999, and his dialogue is a sweet Call-Back to why the v2.0 set of SRB2 versions was dubbed the "Marriage Edition".
- Azure Temple Zone (v2.1)
- Simply complete Aerial Garden Zone's v2.1 incarnation to unlock this level in the Unlockables Hub.
- Adventure Example
- Hint: Beat Spring Hill Zone (v1.09.4)
- Here, you just need to complete Spring Hill Zone (v1.09.4) to unlock this level in the Unlockables Hub.
- Christmas Time
- Hint: Beat the Christmas Demo
- To unlock this, you just need to complete the entire Christmas Demo campaign. Once this is done, Christmas-themed variants of the v1.09.4 levels (Greenflower, Techno Hill, Castle Eggman and Spring Hill) can all be accessed from their respective hubs.
- Getting a P-p-p-p-promotion / Egg Rock Zone Hub
- Hint: "Rock" the "eggs" / A triple trouble challenge shall grant you a promotion
- Unlocking the Egg Rock Zone Hub can be quite difficult. There are three major requirements that must be met to unlock this. The first one is to overcome the Beta Quest campaign, which has Egg Rock Zone as its last level. Second, you need to beat Egg Satellite Zone (whether as the last Special Stage or via the NiGHTS Hub doesn't matter). Finally, you need to defeat Brak Eggman (v2.0) (which, before the unlock, can only be done via the v2.0 Boss Rush). Once you've done that, you can access the area at any time.
- Black Hole Zone
- Hint: Get a perfect report card
- Like in the original game, this level's tough to unlock. To do so, you need a perfect "A" rank on all seven NiGHTS Special Stages introduced in v2.1. Once you've done that, the gate to access it in the NiGHTS Hub will be open.
- Everyone Boss Gauntlet
- To get here, you need to beat all 8 of the other boss rushes in the Colosseum.
- Metal's Challenge - Final
- You need to defeat Metal Sonic in all 20 races of his challenge and acquire each tier's emblem to unlock the final challenge, which is Egg Rock Zone 2 (v2.1).
- History Clash Zone
- To access this level for the first time, you need to beat Metal Sonic at his final challenge. After overcoming this stage, he'll finally surrender the emblem he was wanting to keep from you, and this level will be accessible again at any time from the Metal's Challenge room of the Colosseum.
Campaigns
- Wizard Needs Food Badly
- Hint: Find a loose statue in the museum
- At the outside of the museum's entrance, one of the gargoyles can be pushed off its pedestal. Pushing it into the fountain to the left of the entrance will open the way to a hidden button. Pressing this button will make the campaign accessible.
- SRB1 Remake + Aerial Garden 2.1
- Hint: Beat Beta Quest w/ 7 Emeralds
- Simply put, you need to reach the end of the Beta Quest campaign with all seven Chaos Emeralds in tow. Doing this will unlock the Sonic Robo Blast 1 Remake campaign from both the museum and the Extras menu, alongside allowing access to Aerial Garden Zone (v2.1) from the Unlockables hub. The early versions of Knothole Base for SRB2 can also be accessed from the Development Hub.
- Sonic Doom 2: Bots on Mobius
- Hint: When the race is won and the boss is done, the vent comes loose
- Getting to this campaign is THE most difficult and requires the most effort. To access it for the first time, you need to have completed both the Everyone Boss Gauntlet and all of Metal's Challenge (including the Marathon Level at the end). Once you've done that, a vent will come loose near the Hints room. Going through it will allow access to the abandoned museum. From there, you need to do what you did to unlock the Wizard Needs Food Badly campaign, but with Earless Metal Sonic who broke free from his exhibit. This campaign is the longest one of all, and needs to be beaten to see the game's ending. Once you win, you can access it again at any time from the current museum.
Secret Levels
These don't need unlocking per se. Rather, you need to search for them under certain criteria.
- Emerald Coast Zone
- Hint: Look to the right
- During Snow Valley Zone in the Christmas Demo campaign, looking right at the start shows a more grassy texture. Jumping over there will trigger a secret exit that leads you right over to that level.
- Sonic's Nightmare Zone
- Hint: A nightmare exists for those that go up
- This level is accessible via Emerald Coast, and is located on a higher-up section of land, only accessible by a hidden spring at the first tunnel. From there, a secret exit will take you straight to this brutal level.
- Speed Highway Zone (Demo 2)
- Hint: At the end of the stage, a crusher will start. Backtrack to this pictured room.
- During the Beta Quest campaign, you can follow these instructions to be guided straight to this short level. Alternatively, you can also find it in the Deep Sea Hub by looking carefully enough.
- Hidden Palace Zone (Demo 2)
- Hint: In the lower tunnel, look for fake walls
- Rocky Mountain Zone 2 in the Beta Quest campaign has a lower route the player can take. In this lower route, one of the walls can be walked through, and a hidden exit will bring you there. Alternately, the same method can be done in the Rocky Mountain room of the Arid Canyon Hub to get there.
- Blue Mountain Zone (Version 2.0)
- In the Red Volcano hub, you can discover a wall of debris that can be broken easily. Navigating the path there will lead you to this short development stage.
Characters
- Amy Rose
- Hint: Free Amy
- To unlock Amy, you need to beat all three acts of Mario Koopa Blast (v2.0). At first, it seems like another Your Princess Is in Another Castle! situation, but she quickly proves this wrong.
- If you're not playing as her, she can be found in the cafeteria of the museum after being unlocked.
- Fang the Sniper
- Hint: Defend a train
- To unlock Fang as a playable character, simply overpower his Development Boss counterpart in Arid Canyon Zone's Hub.
- If you're not playing as him, he can be found outside the cafeteria window, bouncing around in the Sapphire Falls arena.
- Metal Sonic / Metal's Challenge
- Hint: Super Search for him. He's Starving!
- While the hint above can indeed unlock Metal Sonic, there are actually two ways to unlock him here. As the hint suggests, access Super Search in the Wizard Needs Food Badly campaign and look for his emblem. You'll find him floating with it. Alternatively, you can take him on in Egg Rock Zone 3 (v2.1) to unlock him. Either way, this will also unlock Metal's Challenge in the Colosseum.
- If you're not playing as him, he can be found racing around the Sonic Circuit seen outside one of the museum's windows.
- Placeholder Sonic
- Hint: Beat Halloween Tech and Xmas levels
- To unlock this very early incarnation of this game's blue blur, you need to overcome both the Halloween and Christmas Demo campaigns. After that, you'll be able to play as him.
- The Demo 3 Pack (Mega Man, Chao and Sinossu)
- Hint: Complete all Demo 3 levels
- This one's a fairly easy unlock. To unlock this character set, you just have to beat the four levels that make up Sonic Robo Blast 2's third demo.
- Easter Invasion / Invader Zim
- Hint: Find the Final Demo eggs
- To unlock the madman himself, you need to locate a bunch of eggs dotted around the Final Demo stages (specifically any under v1.0.8). They can be found alongside the usual emblems of the levels, though have unique graphics. There are 2 per stage (whichever ones don't have a boss fight), and finding all twelve will unlock Zim as a playable character.
Miscellaneous
- Emblem Hints
- Hint: Find your first emblem
- All you have to do to unlock this is find any emblem as your first one.
- Emblem Radar
- Hint: Find the emblem radar
- To unlock the Emblem Radar, you have to locate it in Techno Hill Zone's hub. You can access it by using a pipe that's carrying water from the outside pond.
- Hyperkin
- Hint: Find the 8th Emerald / Need 7 Emeralds, get out of the volcano
- To unlock this secret, you first need to have survived your trip to "hell", courtesy of RedXVI. Afterwards, your next stop is Greenflower Zone 2 (v1.09.4), where, upon reaching the new house, you'll see a note saying that the owner's gone on a picnic. Sure enough, you can find Red having said picnic in the stage. Interacting with him will have him hand over the eighth emerald just to leave you alone. This doesn't have any effect on gameplay, but is needed to access the below secret.
- Pandora's Box
- Hint: With 8 emeralds, jump into a castle's pool / Need 8 emeralds and jump in a pool
- Once you've unlocked the above secret, your last destination is Castle Eggman Zone 2 (v1.09.4). During the button hunt, you need to jump into the central pool, which will tell you that something has changed. It's best to acquire the Armageddon Shield in this pool for what's coming next. Afterwards, reach the end of the level normally, and you'll find RedXVI waiting for you, undeniably furious with your antics. As punishment, he throws you into the pool room with the shield, with several Crawla Commanders flanking you. Defeat them and escape from the pool, then your victory will be earned and Pandora's Box can now be used from the Pause Menu. Like with the original, keep in mind that progress will be wiped until the next restart should you use anything in there.
