Cyborg Ninja (as a hidden fighter) mentioning BB3DS at The Pit from the same game in Zero Hour. Reptile and Cyborg can also do this too occasionally.

Testing stage dealers in Zero Hour with custom stages. Did you know that stage dealers was my favorite addition when BB3DS was in development?

Nine custom fighters can be saved to Zero Hour, as opposed to one in BB3DS. Here, I decided to use names of BB3DS fighters who missed the cut, including its downloadable characters.

Antagonist battle: Corruption Dragon (Zero Hour) vs. Deanna (BB3DS). The latter is a free DLC alongside Blue and Marvin.

ZERO HOUR FACT: Up for some nostalgia? You can use this track to always play when you launch Zero Hour - with a simple file.

Hakase v Flag: The 3rd-party character showdown!

"Destroyed Hapeville" stage, which is unlocked by defeating Super Tac in Story Mode in Zero Hour. This stage plays a suspenseful remix of track 111 from 3D Parkour Pro.

To veteran BB3DS players: If Freddy Fazbear was one of your most hyped characters to try in BB3DS before it came out, I regret to say that in Zero Hour, he is replaced with Flag.

Flag's bio in Zero Hour, which can be accessed by idling at the title screen for some time.

Does anyone think that Flag would retain its 2P palette from 3D Parkour Pro in Zero Hour? You guessed wrong, it uses blue as the 2P color.

The good ol' Pit 1 stage in BB3DS redone for Zero Hour. And the good thing for interested BB3DS players is, Cyborg Ninja can't interrupt matches here - since he is not in Zero Hour.

Flag gameplay in Zero Hour in the 3D Parkour Pro stage, facing Shinko.

I brought one of BB3DS's MMLs to BB Zero Hour. It could, perhaps, be nostalgic for these who has played BB3DS.

Even though the Wii U is discontinued, I still hope SmileBASIC for Wii U comes...

Alpha OS, designed to resemble that of Sbaitso OS 8.1's.

Learn the backstory behind Flag in Zero Hour with this prequel level. Key not available, however.

Upcoming stage from 3D Parkour Pro to represent how "the protagonist of this game" got in Bloodstreams Battles: Zero Hour. A good way to prepare yourself for Zero Hour for its fans out there!

Fun fact: Zero Hour's Corruption Dragon boss battle theme is from this game (although in a remixed form)

Slicer vs Dark Slicer, in Zero Hour. (The latter is unlockable in the game, though)

Lily Polly doing a Microphone Attack on Jolly Polly in Zero Hour. (Note that Lily's sprite is facing the wrong direction, a similar bug occurred on BB3DS)