Fooruman Battles
A lot of work went into FSP. I knew that the pack had to end with a Fooruman boss, but I had no idea how that was going to work, so I made some prototypes. (There's a similar test level somewhere for the Mad Monks in TTJJ2, but it's just the same as the final, so it's not too interesting to look at.) Of course, none of these three were actually used for FSP's Fooruman battle... I forget where exactly that one came from, but I still quite enjoy it. Anyway, these three:
footest.j2l: A very early, very generic tile boss. Shoot some destruct scenery, meanwhile the level attacks you.
footest2.j2l: Clearly this is where Greenkiller was developed, although you can see several ways in which the fight was changed between prototype and final. This has Greenkiller as a miniboss to lead up to the big Fooruman fight, which... was highly conceptual but not actually very playable. Avoid the falling turtles, grab the seeker missiles when they bounce out of the ground, shoot the blocks with the missiles, repeat.
footest3.j2l: My guess is that Black Ninja grew out of this one, but I'm not sure. Perhaps the other way around. I think this provides an incredibly elegant solution to the twin problems of being hurt by the boss while it's alive and then not being hurt when it's dead... the lava tile, for the record, was a placeholder, I'd have replaced it with something with a similar mask but better graphics later. Still pretty cool.

(tileset not included)