Don't doubt your game dev skills, it's all about practicing. If you want to get better at game dev try working on small projects that are different genres. That's what I've been doing for a while now and I've learned so much in a short amount of time. As for making your games more fun, I suggest watching a YouTuber named Jonas Tyroller. Some of his videos talk about very useful tips for making your games more fun and interesting. I hope this helps! Happy birthday!