itch.io

If you carefully read the license page, you'll see it allows you to use it on commercial projects. Yes the title says "Non-Commercial" but I've given supplemental permissions to by-pass that. That was the only way I could give just the right amount of rights to use the sprites. People sometimes criticize me about this but that's what the creative commons support suggested when I asked them what would be the best license for my case. So, yeah, in short, you  are free to use the sprites on your commercial project, as long as you don't re-sell, re-distribute the sprites by themselves.