Nice Sprite. If you just started learning GM though, save yourself the headache, and just do it in Unity. It will be a steeper learning curve, but you'll have a lot less issues, and you'll be able to complete your project much faster, more professionally, and with a LOT less restrictions. You'll also be using a real language (java or C# is what most use) which will help IMMENSELY in the long run!
If you need a good 2d collision engine for unity, I have a friend who has one done he is about to publically release that will do EVERYTHING you would need for a 2D CV (solids, slopes, jump thru plats, quicksand, water, moving platforms, spinning platforms etc.)!