How do you end Chronotron the game when your done the level?

To end a level in Chronotron, you need to reach the exit door after completing the objectives of that level. Make sure you've solved the puzzles and collected any necessary items before heading to the exit. Once you step through the door, the level will conclude, and you'll move on to the next one. If you've finished the game entirely, just follow the prompts to see any final cutscenes or credits.