Fair play to you; designing the core game loop is the hardest part and often greatly overlooked, so merely wanting to get stuck into that aspect is a really positive sign.
I've experienced the same myself; in my first ever game jam (GMTK 2024), I abandoned my idea at the halfway stage because it was too technically challenging and didn't even promise to be fun at the end of it. But I didn't abandon the jam; I went on to submit another game made in half the time haha.
Keep entering game jams, they really are great learning experiences. Best of luck!