The art style's cute, but the resolution makes it really hard to read. Everything's coming up blurry and soft, so maybe upload the pages at a size resolution that makes it sharper? Remember that the maximum width of Tapastic's uploads are 940 pixels, but that doesn't mean the image can't be smaller, that's just the maximum. If you're forcing your image to be bigger to fit the 940 width maximum, maybe just keep it at the size it is (it's a lot easier and safer to make your image smaller than it is to make it bigger).
It's weird to pin what's going on here though because it almost looks too soft in its blurriness to be a resolution issue. It almost looks like you just applied a gaussian blur to everything.
