Hi, ShadowPeterX. I'm pretty new here, but I think I have some useful suggestions.
The first thing I notice is that when I land on your page, I see almost nothing. In the theme editor, you can set an image to display as a default before you launch the game (it's a bit tricky since the image has to be exactly the dimensions of the game window, it doesn't resize automatically). If you can't get that working, consider adding a banner image.
Also, I would put instructions in the description, even though you have them in your game menu. I think having extra information before playing gives people an idea of what they're in for and makes them more likely to click. Also, I would use the default controls in the instructions. If people have changed the controls, they will know what they changed them to, and if they haven't changed the controls, they will want to know what the default controls are. Seeing things like "rotate button" makes it seem like they should already know what a "rotate button" is.
Also, your thumbnail image is really low-res. If you do a search for your game, you'll see that it shows up quite large on the screen and looks pixelated (apologies if that's what you're going for)
I hope this helps, and good luck with your game!
[Edit] Oh, also, you can have a screenshot in an inline game, you just have to screenshots to "Sidebar" in the Theme Editor.