So I have a code-based engine (meaning no GUI) and I was wondering if I use its collision function to make a game like say flappy bird, will it count as cheating if I use it?
Honestly, it's fine! Any engine people build games with these days will have some underlying built-in functions. If it feels right to you, go ahead! There's no voting or winners in TweetTweetJam, so if it feels valid to you within the constraints of the jam, I say do it! :)