Would it be possible for me to use these assets in my unity game?
Absolutely!
Just make sure your project has is using these assets under the following License
You are free to:
Adapt — remix, transform, and build upon the material
Under the following terms:
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licencor endorses you or your use.
Art by - Devil's Garage (twitter.com/devilswork_shop) and Dan Huynh (dribbble.com/danny-huynh)
Non-Commercial — You may not use the material for commercial purposes.