GameMaker Studio Pro for $1, $11 for HTML5. $15 for iOS and Android
It's absolutely worth it. Earlier Game Maker had it's own programing language, but I think now they have incorporated C# into the engine. It's extremely simple and easy to use. I owned 8.0 back in the day. I strongly recommend it to anyone who considers game design as a hobby or something, although Undertale, Hotline Miami and other indie games are made with game maker, so it is quite potent if you know what you are doing.
I played with 7.0 back in the day, made some very basic games, it's a really fun program to play with even if it's 3d engine is not the greatest.
Oh no... 3D is awfull. But for 2D games it's just fine. Especially after 8.1 they have made a lot of things to really push it forward. A basic code used to hiccup on my PC. But looking at things, such as Hotline Miami and Undertale - it's way better now. My only concern is, the multi core optimisation.
I knew undertale was, didn't know hotline miami was GM, I was actually playing it very recently.