(This may or may not apply to only the Jelly Palace. It most likely applies to monster bug in general.)
So, it started off with a thorny jelly cube just walking out of boundaries, completely casual.
It was also quite normal for the monsters to sit there, let me kill them, and have them drop no loot. (But leave an invisible block and empty health bar.)
What had I learned?
A. Jelly Cubes are round, or cylinder shape. Not cubes. (I'm actually happy to know this for some reason.)
B. Sprite skills work like a machine gun if they had 0 cooldown, just hold down the key.
C. I actually discovered my first annoying bug.
Of course, it would not let me progress in this state. And no, the above was not 'normal' or 'casual'.
I've done JK a ton of times, I've gotten loads of Jelly Glue, an Antigua, a Sealed Sword, Brute Jelly stuff... though I've never encountered this bug in any mission or level.
The funny part was, I experienced zero lag, and could use anything in my toolbar. The only thing I could not use is sprite skills. (Refer to C.)
Unfortunately, I was unable to catch any footage of this scene. However, I did get about 7 pictures. (Halfway through the pictures I get me a vitapod. The slimes at the bottom of the screen that you don't see were the only ones that dropped loot.)
1. http://imgur.com/5CXF2cE - Notice the invisible health bars.
1. (Edited) http://imgur.com/FBfmO43 - Image 1 with health bars boxed.
2. http://imgur.com/x3tN5so - Me walking into my new invisible buddy.
3. http://imgur.com/jyhzO8f - Invisible jelly refuses to shake my hand. (Using sprite perk)
4. http://imgur.com/t6rQY2a - Me scolding that invisible jelly for not shaking my hand. (Another sprite perk with the yellow command lines.)
5. http://imgur.com/VlE967h - I GOT THE POWAH!!! (Using charge attack, pretty much showing no lag and that weapons work fine.)
6. http://imgur.com/elZ0DnS - Bomb charge, ditto.
7. http://imgur.com/qNzg0Wl - ^^^^^^^^^^^
What bug ritual?