Update! I managed to un-corrupt it and finish the project! You can find the finished branch here as part of the 256-Series:
https://circuitverse.org/users/4699/projects/256-series

After nearly making it work, and getting my Flappy Bird code quite far, the project corrupted, so currently it does not work anymore. Please look at other Femto-4 forks to see where the project was.