I don't know, why didn't someone mentioned it already,
but if you need to travel
fast in Aquaria, just drink any soup with speed boost and then you can swim throught two maps in 30 seconds.
*spoiler* When you get beast form, it is even faster.
*spoiler*Somewhere on the forum has someone mentioned, that you have to shoot all the time in game, because there are enemies at every step, but you can swim
past them in a few seconds.
Anyway, I am surprised

on how many things people complain in some threads. Most of the game elements, which are for someone painful and wrong,....? I didn't noticed any of these to be wrong (save system, some problems with boss, boring? monotous?,thread
next time make it easier ?!? what?!, ...)
Maybe it is because the Aquaria look like a
never-dying-just-swiming-and-jumping-and-singing-with-fishes-enjoing-the-bright-side-of-life=> danger is none just underwater visual extasy,...so it attracts people, who maybe (just maybe) don't play that often, and then they think its difficult, but in fact Aquaria is game made on hard basic stones of expernice from good old-fashioned game gems and it can't be both
Old-Fashioned Game Gem and
Relaxating Screensaver at the same time.
Conclusion

:
I think, that for a player, who play games for quite a long time, It is
not boring and
not difficult and it has exactly these game elements, that hook us to play it (collecting ingrediens, boss fights, upgradeable home!, costumes!, places, which you can't visit right now, but after getting the right form (CSOTN bat,double jump),.... companions,....)