This was a pretty original concept. I got to 205.6 before I stopped. I found that I could just shoot down the middle and keep going indefinitely.
Since you are new to Godot, I'd recommend you try using GDScript even if you already know C#. It has a number of benefits over C# when it come to game development, and since the last few releases has closed the performance gap on C# in most areas as well.
This was as solid first game.