Jogita6

Are the sounds labeled as Background Music? Just a thought. I don't believe two background music files will play at the same time. Try that first.

No, but I managed to solve my own problem doing something similar. Instead, I just made the music use .wav files, and now it works perfectly.

Just tried it now, but a full uninstall and reinstall still did not resolve the issue. I'm guessing the problem is because of the .gmk that I'm trying to open. Is there a way to restore the factory settings of Game Maker? If the problem is the .gmk, then I have about 4 backups I can try.

Yes. The only exceptions are weapons. You can easily just draw the sprites of weapons, but it's typically easier just to use a separate object for weapons because they often have multiple images. In a bullet hell with false bullets, you'd want to just draw the false bullets. But you can in theory also use tiles for bullets since tiles can have transparencies as well.

Fortunately no weapons are in the game. Though, I still am gonna use bullets.

EDIT: I just finished replacing all the useless instances in the room (Which happened to be about 927 instances ), and now something in the game isn't working/missing. That something just so happens to be the lag! The lag is completely gone!

Thank you all for the answers!

You can randomize anything. And you can use strictly tiles for the background if you recode your engine. Obviously you're too far along in the engine to want to recode it so you're stuck using objects. If you coded with tiles in mind from the outset, that wouldn't be a problem. A thousand instances with nothing in them will still lag the game. It's not the one instance that actually ahs code that's lagging it, it's GM having to cycle through every single instance. Sure, the one object with code in it will alg GM if the code isn't optimized, but the lag is even more noticeable when you ahve to wait for GM to cycle around to that object.

So basically, just keep all objects that actually have something special in it and anything else (Like the level), just use tiles.

In addition to that question:
i want to make a forest. OK, i have my trees as objects. It is not an issue to use tiles, but:
1. How can i add depth to the tiles?
meaning i want to be able to move behind and in front of the trees in that forest... If i use tiles i will be always over them, since they don't have depth...
I can go on different layers and place every tile on different layer, so it will have a depth, but in a forest, 500 trees...
2. Can i randomize tiles?
In my object tree i have 10 sub images of different trees.
If i use tiles can i randomize it, so it will place a random tree on each position?
Again i can do that manually, but again, 500 trees manually...

I can answer #1 for you. When in the room editor when you go to place out a tile, on the bottom should be layer. By default, the layer is 1000000. Just click the "add" button to make any layer you want.
I don't have an answer for #2.