First of all, congrats for the game. I really liked the art and that head movement for Thomas XD. The transitions also are pretty good. It really feels like it has a lot of potential, but there are problems that hinder the fun.
The first thing is that the jump seems to not work so well sometimes, you can see this when you try to from moving platforms, sometimes the jump simply does not work so you have to try again.
Another thing is that you can get soft locked pretty easily. On the first level after you get the gun you can see this. I pushed the enemy that I turned into stone way too much and the platform stopped halfway and I could not make it go any further. This way I could not get down and so I had to restart the game to pass it. I suggest you add a button for reset for this problem.
And then the next level seems kinda impossible? Like, I can't jump to the right because it is too high for the jump. And all I can do is freeze the enemy for a moment by going to the left and making the gun pass that wall. Then I get a platform that I can't reach... I really don't get what I should do here...
Well, that's about it. All in all, it seems like it can be a very good game if you fix some problems and make the challenges a little easier.