Quick Mention: Parsec
Parsec is a tool that lets you remotely connect to someone else's computer and control their mouse, keyboard, etc. If you're working in a team, it's worth checking out as a way to make collaboration and helping each other more convenient.
Free Assets
Note: Please pay attention to the licenses, they let you know whether you can monetize your game or if you need to give credit, etc.
| Link | Resources | License |
| https://opengameart.org/ | Art, Sound | Depends on poster, check the description for each asset |
| https://www.kenney.nl/assets | Art, Sound | Public Domain - free to use for any purpose, no credit needed |
| https://www.zapsplat.com/ | Sound | Free to monetize, but credit required - check the website |
| https://itch.io/game-assets/free | Art, Sound, Everything | Depends on poster, check the asset's page |
Free Tools
Note: All assets made using these tools are legally yours, so no licenses to worry about
| Link | Description |
| https://led.itch.io/tilemancer | Generate 2D game art using a node editor similar to Blender nodes or Unity's shader graph |
| http://sfbgames.com/chiptone/ | Super easy tool for making 8 bit style sound effects in your browser |
| https://joshua-maros.github.io/audiobench/ | More complicated but very powerful node-based editor for making sound effects |
| https://boscaceoil.net/ | Easy music making tool with a tutorial (supposed to work in browser but only the download link works rn) |
| https://beepbox.co/ | Easy Browser-based music making tool! |
| https://moddedbeepbox.github.io | More advanced version of beepbox with more settings to change, if you're into that |