After 4 years, I received a message on Reddit from a user who recently downloaded my game, and a glitch on Level 4 prevented them from continuing. Not letting a fan get turned away empty-handed, I rewrote the entire game, consolidating the 13 "mini-engines" to one, fixed all bugs, and slightly tweaked gameplay.

Download:
http://www.mediafire.com/file/fkz3j8zwhcpzrt0/sourceseekers.zip/file

It's also available here (or at least when it's accepted into the archives):
https://www.cemetech.net/programs/index.php?mode=file&path=/84pce/basic/games/sourceseekers.zip

Customer service!

Did you receive any feedback from the user?

Yep! They said the first level was broken, so I fixed it and resubmitted it. Other than that, not yet, although this was only yesterday that I built it at all.