Help in GameMaker

Hello, I am working on project for OperaGX + GM JAM but faced with strange error: Uncaught syntax error. I explained problem in details in this topic:
https://gamejolt.com/f/gms-2-html5-uncaught-syntaxerror-unexpect…

Hi! I am making my Opera GX Game Jam Game and i have a question... I can use no-copyright music? Thanks!

A little question here. May I publish game now,but then constantly update it until 14 august?

"The game should have local multiplayer OR be designed to easily include local multiplayer."

can that means i can create a server without using html5 project?

About the OperaGX Game Jam. I made a game that can be seen only by dark theme users. I have no idea how to make it adapt to light theme automatically so I was wondering, can I upload a separate version of the game for light theme users?

Hi there, where can I find the graphical-guidlines for the "UFO-Theme"? Thanks! :-)

I have a doubt the game does not matter if it is retro in or in 2d?

I have a question about png crus, me and a friend tried to use png crush but it only saves 1 byte (my friend) or no bytes when I tried it, and the gml_parama page doesnt really help

Question for the Game Jam(1/2):

For Co-op, The technical guide states "[your game] should be entirely playable on the keyboard and not require a gamepad to be connected". Does this mean we cannot use the mouse for any in game inputs?

I have a question, the player has to be an UFO or it can be a human and the enemy an UFO?