Achelous is a Super Metroid hack by a guy called "Exister" that was made for the recent Starbase Contest on Metroid Construction.
The hack, in the state it was originally submitted to the contest, got lambasted by reviewers. Enemies hit like a truck (50 damage each), were unfairly placed, and it was easily possible to get to one of the bosses before having any equipment that could damage it (forcing a death). However, its worst sin (directly in the eyes of its haters) was its visual aesthetic. The author turned the dial for bisexual lighting past any reasonable maximum, resulting in an experience that would give you eyestrain as you tried in vain to distinguish foreground from background. (One hater said something to the effect of "it sure isn't bi visibility week here" while playing it.)
Fortunately, the author recently released an update that addressed all of the major concerns people were having, turning the experience into a perfectly tolerable (if somewhat difficult) romhack in miniature.
Anyhow, I keep making jokes about this being called Super Metroid Achewood but so far only like 2 people have laughed. (Please clap.)
(As always, you can find more metroid romhack maps on my site.)