The following is a short list of key known issues. A more complete list of and discussion on bugs and planned features can be found in the FLAT GitHub repository.
Arch Linux users have reported crashes when initialising audio. A workaround can be found here.
Bugs should be reported on the issues page of the FLAT GitHub repository. Please search for any existing issues that might cover your problem before submitting a new one.
When submitting a new issue or commenting on an existing one, please try to list relevant information, such as the operating system version you are using, and whether or not you have compiled from source, used an existing build or customised the game in any way.
If you have trouble with GitHub's issue system, you can email Cheese, who will attempt to either look into your problem, or create a new issue for you (depending on how much free time he has).
When run from a command prompt or terminal, FLAT will generate output that might be helpful in understanding problems.
Some yet to be identified problems (such as enemies not spawning) are intermittant and may resolve themselves after restarting the game (if you encounter an ongoing problem that does not appear in the list of issues in the FLAT GitHub repository, please create a new issue to make sure we are aware of it.