Game jams often are so short in time, you might want to focus on game development and not on creating the visuals for your video game. There are tons of free asset packs that can be used to help you work on the coding side of your game, especially if you cannot find an artist to work with you. Some of these kits are free or give a large portion of the sets for free, which can be especially useful when creating games that aren’t going to be sold.
Kenney’s Assets
Kenney, also known in some communities as “Asset Jesus”, has a ton of different assets that can be used for free, for game creation. His website easily allows you to sift through 2D, 3D, and Pixel asset packs. Once you know what style you want, you can then explore different genres like platformers or dungeons. Kenney also has UI packs, Audio packs and textures, along with some tools that can help you on your indie dev journey.
OpenGameArt
OpenGameArt has been around for quite some time, as a community-drive website full of all sorts of assets. Though these aren’t often in packs like others on this list, there are a lot of retro and pixel assets that can be used. You can also submit your own art to allow others to use it and there is a section which showcases popular art for the week as well. If you are looking for something specific, this is where to go.
Shubibubi’s Assets
Shubibubi creates free to use asset packs that all feel very cozy and pixelated. At the moment, they are working on creating more of these packs, but if you are making a cozy farming or fishing game, they have plenty of assets for you to use for your project.
Pixel Frog
Pixel Frog has a few select asset packs that all have great vibes to them! They are complete free to use, and you can see them in action through gifs on each page, seeing how well they animate. These graphics are all marked as Public Domain and aren’t used in tons of projects, so won’t look too much like other games people have seen.
Craftpix.net
Craftpix.net is a website that has a number of free and premium packs of assets. Many of the kits do have additional information on how they work and there is a big mix of primarily pixelated styles. They also have a subscription model that will unlock a large number of assets all for one price. It’s worth looking through if you are looking for some simplistic asset kits.
Kay Kit
Kay Kit creates fantastic asset packs that are 3D models. All of these have a real charm to them and feel like they could do well in a number of different types of games. Kay has a few different kits that all gel together very well and is adding more over time.
There are probably a lot of other asset packs that you can find on the internet, but these are good starting points, especially if you are looking for something free to use while you focus on the developing side of your gaming journey.