All game characters, graphics, sounds, and other materials are property of their original creators and copyright holders, and are provided here for private or non-commercial use.
When we join to a GameJam (like GithubOff), we are looking for fun and not profit propose, (a private or non-commercial use ) so, based at this terms can we use these sprites in a gameJam or not?
That doesn’t necessarily apply to the “Arts & Crafts - Sprites” section of their associated forum, though. Some of them are user generated, some are WIP-rips.
Oh, so it’s ripped graphics from a commercial game. Then I take back my answer. You can perhaps use that kind of graphics as temporary art, but you should be careful with releasing anything containing graphics that you don’t have permission to use.
I’d look for free/paid game art that you’re actually allowed to use without any problems. Perhaps some of the assets on itch.io. https://itch.io/game-assets