The good
I think you created some new original cute characters
Some animation, but you gave up on animation near the end by not animating the legs & such.

The bad
There's too much text which moves fast to read it all. Find a way to reduce it as it kind of repeating the same or similar stuff.
Maybe its the sleep plot, the music & the story is boring me to sleep. Was that the plan?
Even when ripping off 3 animals tails there's no blood or mumbled screams of death. Happy Tree Friends looks violent but its actually about 3 frames & then the blood just sticks around like a shape between the head & eyes/nose/mouth. Anything longer is typically a loop.

Happy tree friends is not just cute & cuddly. More importantly they didn't just stand around talking. For example "staying alive" start with a tea party until disco got them dancing kind of & "Tongue Twister Trouble" revolved around cute kitten turning a tongue into a pillow by first slow padding it to horror of the ant eater & then slicing off the extra.