First of all, you need a working copy of GameMaker Studio 1.4 or 2 and a copy of the project files which you can download from GitHub. (Check the image below to see how)

In order to add enemies into GMEA, all you need is a bit of programming knowledge and a sprite.

First of all, add the sprite into the Sprites folder and give it a name you can recognize later.

This is important so pay attention, the sprite x and y origin must be set always at the following coordinates. In the case of a 32x32 sprite you set them like so:


Remember that the y origin must be set always 16 pixels above of the bottom of the sprite. In that way we ensure that the sprite will collide with the floor correctly.

You will need to set a mask as well, to do that just click on Modify Mask and a new window will open.