Project Spark looks like it will be an absolutely beautiful game. Unfortunately, it has a fatal flaw for me.
I find it irritating.
"What? NO! REALLY?!?"
It's the same problem I have with the toy box on Disney Infinity.
"But why, random stranger on the internet? People love the toy box and all of the things you can make with it!"
That's cool. If you enjoy making your own content in a game then go right ahead. Some people make really fun content, but I just plain do not want to be bothered to make my own game.
I've thought about it before. My friends and I have laid out storylines and rough sketch concept images. I played RPG Maker on psx, and I spent an unreasonable amount of time trying to make a fantasy epic that never worked out the way I wanted it to. I've even gone so far as to create D&D campaigns complete with maps and props that could be used in a game. (I took the monster manual and completely reworked/created dragons so that I could have a my part end each leg of the journey fighting an epic dragon boss battle. I worked in some video game mechanics too where the party could only do damage to the boss for a set number of turns provided that certain criteria were met. The shadow dragon could only be damaged when he was stunned by beams of sunlight, but the fight started in a cave deep in a mountain.)
I realized after that ... It's more trouble than it's worth.
I'm not an "indie" developer.
I don't have the aspiration to plunk hundreds of hours into some project that will never give me any kind of monetary returns. But more importantly, I don't want to drop hundreds of hours into some creation that I care about only to have it not turn out the way I envisioned it. I play games to escape the stresses of life. I do not play games to add more stress because my creation is crap, and I need to fix it.
It's just one more thing on top of an unending pile of crap that needs to get done.
When I play Disney infinity I'm either playing one of the pre-made levels or downloading something from Disney directly. To do otherwise is just an exercise in frustration for me.
I'll likely play the games other people make on project spark... There just might be some really fun diamonds in the rough, but I'm not at all interested in making my own.
I really just want to throw money at steam, the Nintendo eshop, psn, xbla or a register jockey for a quality piece of programming magic that will entertain me for hours.