Thanks for trying it out, even though it's not your genre!
An always visible indicator, even when the target is off screen is a great idea!
Design wise, the concept for the whole game was speed and precision, hence the tiny platforms, but yeah, I agree that the platforms might be unnecessarily tiny.
Also, I don't know if you were playing with the sound on, with headphones, but the game has directional audio, so when a new target spawns in, it makes a sound, and you can get a pretty decent guess on what direction it's in by that sound.