It's a ZZT version of Ecco the Dolphin, which is probably my favorite game. In my version, as well as the original, you play as Ecco and attempt to navigate the treacherous sea.
I should mention that there's really no plot to what I am uploading here. It's an unfinished game. I also can't guarantee you won't encounter bugs. It seems like once your worlds and boards get big enough, ZZT starts getting unpredictable.
Have at it and let me know what you think.

edit: I was able to get it running okay in Dosbox by setting the dosbox.conf to "cycles=40000", for what it's worth.