It says it's free to use in commercial projects but then right above it it says non commercial (NC)
Viewing post in FREE Low Poly Weapons Pack comments
Sorry I thought this was one of my newer projects where it's made more clear:
Commercial use is exceptionally allowed when using these assets within a commercial project, not reselling the assets, not focusing a project around the assets, and not transforming a project from free to commercial as the assets are added, for example, as cosmetic rewards.
This means you can use them for your mobile game as long as they have no commercial value themselves, which I imagine they won't, and you follow the Creative Commons license's other terms. Hope this clears it up. Good luck with your project, and don't forget to share a link here when it's done if you want to.