I’ve played it a few times, and the only way to get through the game seems to be to press the spacebar immediately after launching it. If everything goes right, an SFX plays that reminds me of something being crushed. That’s when we get to see the ending.
If we don’t press spacebar and don’t hear that sound, we’re basically doomed to lose. There isn’t enough time to load the weapon and fire it.
I’m not sure if this was the intended effect.