Thanks for trying it out!
You have to keep the meter filled with energy, but empty or overfilling it will kill you. The health will be less confusing in the next update as we redid the UI to show this better.
I am really sorry about the checkpoint issue! It will be fixed in the next update. Until then, you can delete the save at "%APPDATA%\Godot\app_userdata\Crashed Mech\savegame.save"
Thank you for your kind words!

