Sweet level. Off the bat, the music choice seemed a bit confusing to me, but once the barrel section kicked in, I think it fit really well. I like how you stuck to a few key enemies and varied them really neatly. It's cool having to fight a hammer bro on the ground in one section, and in the next section, having to avoid that same enemy but while shooting around in barrels.
Speaking of the barrels, I think that was the strongest point of the level. I wish the element was used more liberally in the beginning, and like MegaDood said, the end. Specifically, I think it would help to have had a more thorough introduction to the mechanic for those who haven't placed the DKC games. Maybe you could have had one earlier in the level in an empty location void of enemies (so the player has less to focus on) that could be simply jumped into. Currently, players have to risk jumping a huge gap to try out the mechanic for the first time.
Also, maybe the music could have been grassland ambiance until you activate this new first barrel, triggering the guitar to kick in. Or maybe not. I'm just a sucker for dynamic music in my levels
I also wish there could have been more secrets. I climbed all over the place using the vines, and each time I got to an interesting little alcove or pit, I expected secrets, but didn't find many. The ones I did find were cool, I just wish there could have been more of them.