Wonderful work!!!
Nice first submission. Starting with a flappy-bird style mechanic and then introducing different challenge patterns was a smart choice because it keeps the gameplay from feeling too repetitive. The moment where the world switches is a cool surprise if you go in without knowing about it.
The core mechanic works and it’s easy to understand what the player needs to do,.
One thing that could make it even better is gradually increasing the challenge as the run goes on so the tension keeps building. A few extra sound effects could also make the actions feel more satisfying.
Overall though, this is a really good starting point for a first game jam. Keep going with it.