That was a neat little game. It's short, but I think it's as long as it needs to be. It has a lot of charm to it, too, and reminds me a bit of an old Flash game.
There are a lot of nits I could pick. The homemade grappling hook probably wouldn't work, and all the items being conveniently there pushes suspension of disbelief. The game has an inventory, but you don't use items from the inventory and sometimes ones you shouldn't have anymore don't disappear. The music is a bit too loud.
But ultimately, I'm nitpicking. The game is short enough that nothing really grows from a brief thought at the back of your head to anything that really sullies the experience.
I think if there's one complaint I'd really level it's that the art is really inconsistent in both style and quality. There are some beautiful handpainted backgrounds, but these clash pretty heavily with the almost mspaint looking foreground objects and whatever style the lighthouse is supposed to be. Having to work with whatever stock assets can be had and whatever can be scraped together can be rough; I'm not an artist and I've been there. Ultimately I ended up trading fidelity for consistency in most of my projects.
That being said, the visual contrast does make finding objects much less of a pixel hunt than it could have been.
All in all I think this is a pretty solid game. It's simple, but it doesn't overcomplicate things.