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As long as the final build is playable on a Windows machine or in browser, you can make it in whatever you like!

A lot of people enjoyed using GameMaker Studio 2 and Unity for building their games in this jam last year. GameMaker 2 are even giving full access to their engine to participants for the duration of the jam, and giving away free copies to the winners! There's always a ton of community support for engines like Unity and GMS2 simply because they are very popular, so you might consider using one of those in a high-pressure project like a gam jam.

That said, picking the engine you're most familiar and confident with is probably always going to be the best bet. Good luck - can't wait to see your game!

would a mod to a game you don't own count?