Anyone who can help how to unlock the training mode?

I just played a survival run with 2 other friends in local co-op we got I think a good 1st try we made roughly 2 crystals I think before I was the first one k'o'd my question being after revive timer times out and your Portaled away with a game over is it possible to come back if your friends do well enough? Or are you just screwed only able to watch, my friends died to a boss shortly after so I don't really know the game over extent? And do you still get 1ups ever 100 points?...

TMNT: Shredder’s Revenge - Radical Reptiles DLC | Available Now Source: https://www.youtube.com/watch?v=-lr7Pw22VcU Where?

Casey uses a basketball? Where does he keep it? Who the h thought it was a good idea. Still Will not buy

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