One of the "DELETE ME" items can be picked up. It looks like an animated red orb and, when collected, gives you "6 Deathcoils". This is ammo for the Ripper Heart, but it doesn't actually give you the Ripper Heart if you don't already have it.


If you kill yourself in the beta, even just by fall damage, you get this message:

I also found the old Sumo boss. Rather than reside in his Sumo Sky Palace level, his boss arena is located at the end of Dark Woods of the Serpent after the magic carpet ride where the Serpent boss is normally first encountered.

For the most part, he just walks around aimlessly, but he does occasionally perform two attacks: the leg stomp and bending over to fart at you. Both of these attacks play their appropriate sounds, but neither do direct damage. However, the fart attack occasionally spawns the gas grenade effect in the room which harms you if you walk into it.


The Sumo doesn't perform his thunder clap attack although he has the art for it. He can be killed, but it doesn't end the level and he doesn't do a death fart like his finished counterpart.
There's also one other unique detail here I found amusing. The Sumo's lair is decorated with his steaming turds:

In the beta version of Floating Fortress, the biohazard chamber in the ship housing the Serpent Apprentice was originally a chamber filled with a bunch of Baby Rippers:

I think it's quite a bit creepier than a mini-Serpent seeing all of those guys clinging to the glass and looking at you from inside there, but there's also a button nearby that activates a crusher which kills them all, so they're not much of a threat. However, I point this out because these Baby Rippers combined with the original Sumo boss placement in the woods provide evidence for my upcoming point.
In the beta version of Stone Rain, the final map of the game taking place on and in the volcano, the interior of the volcano is bereft of machinery and much more cavernous. In the final game, the caverns were heavily cut down to just hold the Ninja Turtles secret. However, here in the beta, these caverns are the setting for the final boss fight. And who's the boss waiting for you here? Take a look:

(Screenshot taken in Redux because I couldn't noclip to this part in the original executable)
As you can see, it's the Serpent boss. Since no other Serpents or mini-Serpents appear in the other beta levels up to this point, I offer this hypothesis for your consideration: The Serpent was originally intended to be the final boss of Shadow Warrior.