I checked out The Sandbox Evolution and enjoyed it a lot. The Platforming was fun and the levels I played were short.I normally am not a huge fan of platformer games but the short levels and easier difficulty were more my play style. With that said they do have harder levels, and you can use your credits to automatically beat them if you end up on the struggle bus for long. Beating Levels and completing quest in game give you more credits to use. You can also build levels to share with others, the tools are easy to use and after a few minutes you quickly figure things out. You unlock everything using credits, once unlocked you can use them in your level design. Early on I still had a ton of credits and no problems getting the items / monsters / materials I wanted to use, but I can see where the free to play isn't so free once you get into it. With that said I have no problem forking over some cash for a game I'm enjoying and spending lots of time with. So check it out on steam, it's free to play and you should be able to get many hours of play out of it before you hit that first $ roadblock.
Here is my first look video.