Sorry for the double post but the exams are over. Man, they sure didn't hold any punches this time around, but whatever. I've got more time to work on the game again.
Here is an overview of the recent comments and there status (I'll post it in the first post as well):
1. Game can become more sluggish as it progresses
--> Surfaces are freed up more thoroughly in the next demo. This should improve memory consumption a little.
2. Weird thing happen with the keys pressed while the game has slow framerate. This possibly due to the manor in which Gamemaker tries to catch up, with the key having been pressed, when it falls behind.
--> I'll remember the issue for now. A solution might be to handle keycommands in a different manor. Changing such a thing is easier as I continue tidying up the engine/coding. The problem also sounds like a result of very slow framerate so I'm not sure how many people have these issues and what priority I should give it.
3. A surface error happens when entering and exiting the dungeon too many times.
--> Solution in progress. Repeating the exact same action several times in a row should basically net you the exact same result several times in a row. I'm unsure why this is not the case. Maybe it's a Gamemaker problem with surfaces.
4. On slower computers serious lag may occur when you cut up (multiple) grass, pots or enemies.
--> I'm unsure why this happens with enemies, but I'll see if I can work on removing the slowdown for grass (and possibly pots). When objects like grass get destroyed the ground is edited. This is done by reading an external file and editing that data in a new temporary file. The reason for reading the external data every time you destroy something is to spread out getting the data as oppossed to reading in everything the instance you enter a new room (that could currently result in slowdown on better computers as well). I'll work on this problem.
5. Pressing Ctrl+Alt+Del deletes all surfaces (= Gamemaker mechanic), resulting in errors.
--> I'll see what I can do. Half the problem should already be solved when number 3 is finished.
6. Link looks like he is standing in front of a statue while standing behind it (= reoccuring problem with various other objects as well).
--> Solving this properly will require a thorough rewrite of some mechanics. This one will be pushed back to a later date.
7. The walkingsound will sometimes continue the loop while Link has stopped.
--> No solution ready right now.
8. The items created by flying skulls can not always be collected.
--> This happens if the items are created on a different floor then you are standing. Fixing it will required quite a bit of time but may also result in solutions for a slight problem with the Pol's Voice.
9. The dungeon can currently be done out of order resulting in unclear goals and closed doors you can walk through.
--> I'll try to adress this before releasing the next demo. This will require me to finish the firerod's magic and torches to light.
Brutus: The only thing that I can advise is that you try again. Not unpacking everything like intended might also result in weird behaviour. I've never tried it.
Edit: fixed issue number three (and one a bit more as well). There was another large surface that was not freed up properly which somehow resulted in the surfaces getting deleted all together. Maybe the overall memory needed for surfaces became to large for Gamemaker as it was a pretty bad memoryleak.
Edit2: Improved some mechanics and that eliminated the temporary decrease in framerate when I cut up multiple bushes at once (on my slow laptop). I'm unsure if this will also fully fix Niek's problem since his decrease was worse, but that will have to be tested when a next demo comes out. I'm considering number 4 closed for now.