The thing with designing a game is you end up playing it, a lot. And things become second nature, you know the quickest route, things to avoid and so on. What's obvious to the designer though, isn't always obvious to the new player.
So, if you don't think you're getting very far, here's a few hints.
1) You can stun certain baddies
Jumping on ground based baddies (knights, chickens etc) will stun them for a while, while they are stunned they are vulnerable to accidents happening (stray cannonballs, arrows, falling spikey balls, stalactites etc). Occasionally you will be rewarded with MegaParsley (its magenta and will fully restore Cocoas health) for causing accidents.
2) Don't eat all the Parsley
Remember, there's a pandemic, Parsley is in short supply, each Parsley will restore Cocoas health by a third...so eat it when you need it, not just because it is there
3) Go East!
When you get to the castle and go down into the burrow, don't go west (there's a demon knight with a canon, don't go for the chefs hat (plenty time for that later, and if you help the right people that way can be made a lot easier!)
4) Cause as many accidents as you can
Causing accidents, and the right accidents, is the route to success, not only will you occasionally be rewarded with MegaParsley, but its also the only way to recover some of the artefacts.
5) Talk to the NPCs
They're the ones with speech bubbles, they wont hurt you, help them and they'll help you
That's probably more than enough to get you going!