I also have Unity and GameCreator but they are a little more complex and I want my first game to be a little easier for me to make even though it probably is going to take me years to make it so by then I will be good at whatever program I'm using and could use a harder one. They both have free versions so money isnt the problem until I want to publish and make money off the game.
I very recently decided to make (2D) games, and after dabbling shortly with GameCreator (wich i've thrown away since i found the way to script stuff awkward) i decided on Unity.
I know it's not your first choice, but after spending a whole bunch of hours with it, here's some impressions that might help you to find out if you'll like it or not.
1) Unity has only very recently started to actively support 2D. Keep that in mind if you are looking for tutorials and such, as many of them deal with getting around Unity being 3D and call functions and classes that now have better equivalents for 2D Gaming.
Also, i guess it serves as a word of warning that other Engines/Tools/Programs are probably better suited for specific needs when it comes to 2D Games, but, well...
2) My Reasons for choosing Unity were mostly that it is popular, with being powerful a distant second
- As such, there are s**tloads of tutorials, (answered) Questions and other material out there to learn from. Basically every issue i've had so far was solved by googling it since there are tons of people who've gone the same way. PLUS there are lots and lots of Plugins you can get for free or for money that either expand on what the engine can do or make things a lot easier.
3) Yes, you'll do need to learn scripting, and yes, that can be quite complex. However, learning to program can be valuable outside of Unity (ESPECIALLY if you choose to script in C# as opposed to Unity's JavaScript-Based but propriatary language) and opens up a lot of stuff you can do with your game as opposed to "easier" Game-Making-Tools
4) Despite that, Unity's Frontend is pretty easy, logical, and let's you try out stuff quick. Even making a build of your unfinished game is extremely easy.
5) EXCEPT for UI Stuff, both menues and on screen displays like scores or whatever. That is needlessly complicated and stupid and luckily will be fixed soon...but not yet.
6) Here's the Tutorials that helped me the most. I didn't recreate the games within, but i used them as a go to resource for learning the first steps of my own little game.
http://pixelnest.io/tutorials/2d-game-unity/
http://www.raywenderlich.com/61532/unity-2d-tutorial-getting-started
7) The first site also has a great list of links that are guides, tutorials or just interesting stuff about making games.
It also has linked the extremely cool "Game Mechanic Explorer", wich gives you shortcuts to how basic game mechanics work, like for example having a jumping/running mechanic that feels good. The Code isn't written for Unity or any of your other choices, but once you get the hang of coding, you should be able to translate them for you: http://gamemechanicexplorer.com/
I hope this might help with your decision.
Also, regardless of your final choice, you should read the "Make Games" Tumblr. It's a few Blogposts by Derek Yu, Creator of Spelunky, talking about what he learned on his way to become a "real" Indie Dev.
I especially recommend the following:
http://makegames.tumblr.com/post/44181247500/making-it-in-indie-games-starter-guide
http://makegames.tumblr.com/post/1136623767/finishing-a-game (Not a guide about how to finish a game, but a few pointers on how you should handle a project so that you WILL finish it)