Hi Eric, first of all thanks for your feedback for stage 4! Some answers to issues you pointed for my entry ("The Castle"):

Level loading seems to be quite long
That's because loading creatures takes long (animations must be generated, along with display lists). I improved it after stage 4 deadline --- it's about 4x faster now. On the other hand, new creatures will be added before stage 5 deadline, so the whole process will probably get slower again

In any case, loading creatures happens only when loading the very first level, when loading further levels (or ending game and executing "New game" once again) creatures will not be loaded again, so this will not slow down the game between the levels.

Movement is blocked by dead aliens (which aren't visible when you're blocked on them, too low and flat on the floor), you can also get "stuck" when colliding against a wall, instead of sliding.
These are 2 known problems. Problem with being blocked by dead aliens should be fixed before stage 5, hopefully sliding along the wall will also be improved.

Default movement controls key setup is also quite uncommon
Hmm, they are much like normal Quake/Duke/Doom controls, before all the FPS games started to use mouse to control player rotations... Mouse is used for picking in my game (this will probably not be changed before PGD compo end --- too little time).

In any case, stage 5 submission will have a menu to configure all key shortcuts, so I guess this closes the issue

Finally, readme and text files are UNIX-style, which means notepad and common Windows text viewers won't display them correctly (okay for me, but be aware many end-users will be unable to view them correctly).
Good point, I changed line endings to DOS-style for README and TODO files. The rest of the text files is not intended to be read by end-users, so I guess it's not a problem.