Thanks for posting, in my option (Alec doesn't completely share it, obviously) the fact that you care enough to let them know what they need to fix (in your option) is a pretty good indicator that you'll be a good person to give out constructive criticism.
Anyway, about monotony;
What I've picked up from not only my game experience in aquaria, but what iceD was trying to say is; The long 'monotonous' parts of aquaria aren't about just getting from point A to B, it's about enjoying the journey. It's to show how large the world is compared to Naija, and how devoid she is of companionship.
Now, I understand how this doesn't float your, or many other people's boats, But some of the hugest games of these last few years are five-bazzilion times more boring then traveling in Aquaria ever will be. I'm thinking of WoW, Everquest, Guildwars, and many many RPG's that feature grinding. Killing enemy after enemy, each with the same series of attacks and death thralls, you using the same boring combination to kill them...just to get that rare item drop...
I think I've made my point. But to add to that, in Aquaria, you can easily get faster forms. Spoilers
By going to the kelp forest after the first boss, you can grab the fish form which dramatically speeds up travel. And the beast form after that also speeds things along.
There are plenty of games on the market that get just plain stale from playing them. That's one of the things the dev's worked so hard on in Aquaria; They did their best to make every area different by featuring hordes of enemies, and boatloads of different wildlife; they wanted Aquaria to have as much eye candy as possible, so it wouldn't get boring. They tried their best to make it so every time you went exploring into Aquaria, you'd find something new.