Bugs I've found so far: (I left a more thorough comment on the youtube post before realizing this here would probably the better place for that, sorry ^^)
If you die over the water in the boss fight (for example by rolling into a shockwave) and jump down again after respawning, you will be placed at the edge you died at, which lets you bypass the boss completely. Works both for the northern and southern gate.
Deflecting the ranged attacks while standing right next to the boss will make them phase through it with no effect.
Falling into the northern-most chasm directly right of the two high bridges by the area with the shockwave enemies will respawn you right where you fell, instead of at an edge. This lets you move further in that chasm and even to the area between the bridges by either walking or rolling (and immediately falling, respawning right where you fell, repeat)
Falling with the skateboard shows the skateboard being equipped upon respawning, despite that not being the case.
The phone reappears in the starting house after exiting and re-entering.
If you lure a scorpion up to the east edge or north wall by the bench just south of the village, they will flicker between left-and rightfacing sprites.