I like this idea very much (including these little squeaks, awesome :D ), though the goal and UI should be improved to communicate with player better. I'll give you a run-down of my playthroughs to help you understand what I struggled with:
- first game starts: I have a star and a sphere, I know that arrows move and space shoots. Okay, let's give it a spin
- I start flying and notice that something like a trail points in the direction I'm heading in. Okay, that's not intuitive, but I assume that's not a trail after all, I guess after something happens I'll know what it is.
- Nothing happens - in the sense that I don't encounter anything on my way
- okay, let's try shooting. Shot produces a ball which I seem to be attracting. Ball floats my way, through me, and finishes on point opposite to where it started on a sphere. Oh, so it's like a floaty powerup from r-type to block something?
- I start floating in another direction, my ball hits me and I'm dead. Well, didn't expect that. Why did it float through me earlier?
- After a few more tries I manage to float with more balls without hitting myself (usually keeping constant speed and and loop [release one ball while holding down, next ball while holding down+right] works like a charm, and then when I release the final, big ball... I die almost instantly. After > 10 tries i gave up for a while.
** core issue **
The problem is, I still don't know how to exactly finish level 1. A simple tutorial-like level with just one small and one big ball would be a **huge** help, I suppose, to give player ability to complete one level and get the hang of mechanics without concentrating on keeping alive, and to show them what are the win conditions - for now **I know that it's my fault** I die, but I'm still not sure **what to expect**.
Secondly, I find the trail pointing in the direction of travel a tad confusing. If it looks like trail, I expect it to face opposite direction, and it just feels wrong (I find that I concentrate on it too much instead of paying attention to what's happening with the projectiles). Especially since projectiles leave trails behind, not in front of them like the player.
** So, in short: **
- trail: if it's a trail, make it face the direction opposite to travel; if it's not, change its appearance (if it's supposed to be velocity, maybe an arrow? )
- Level 1: make it have just one/two small balls and one big, to allow player to easily finish it and learn what to aim for and expect at the end of level
- add some clear introductory text.
** Regardless, I think you did an awesome job that just has a bit hard time communicating with a player **
I really like your concept, that's why I'm writing all of this. I hope it'll help you address the issues players might have, to allow them to pick up the game more easily. It's clear that you've put a lot of hard work into this game, and it would be a damn shame if players couldn't play it properly. Art is great, audio fits perfectly, spin on the theme is fun, and the gameplay is fluent.
Please give me a shout if you're able to put some update, I'd love to give it another spin. Cheers!