For anyone who might be interested, I've posted a rather elaborate walkthrough written by Bert Jamin for The Five Cores.

It's 20 pages long and has tons of large images.

I don't want to consult the walkthrough just yet but I would appreciate a hint about my aim.  What the HELL am I supposed to be doing?  So far I've transported myself around the island, fiddled with cogs with mixed results, pressed anything I found that could be pressed - generally with no results, climbed the lighthouse where I had my signals to a passing yacht ignored (Terry - I know it was you) and amused myself rolling barrels down a hill that I suspect I may need later.....

I just want a hint - why am I there?  What am I trying to do and where oh where is the chocolate?

The chocolate is in the cake, but the cake is a lie

You're supposed to be wandering aimlessly across an island randomly pressing inanimate objects and hoping they spout pearls of wisdom (or at least candy) and tanning/becoming beef jerky/baking in the glaring sunlight.

Best game ever right? Sounds like what I'd do alone on an island, going crazy. 

You are no help at all - but you knew that, right?  

Well, I suppose you could always ask Bert Jamin...

I just opened my front door and flung some chocolate in your general direction.