Yep, sure. Remember that this jam is to challenge yourself, so if you feel like you're going out of bound regarding the rules you'll only be cheating yourself ;)
i'm bad making characters, but having a specific asset to use helps A LOT, when i start a jam i get stuck on what to draw, and this accelerated the game i'm making so much
and I want to ask one last question ... In the tileset I’m using, the background is black, but the game I’m making doesn’t have a black background, so it makes the itens strange, can I make a transparent background on some items in this tileset?