What I like :
- Sci-fi Mood
- Minimalist design
- Good light
- Sounds and particles
- Concept is nice
What can be improved :
- Some tutorial (I have to read the previous comment to get to level 3)
- Weapon control are complex without any reason. Simply aim with mouse down, and fire with mouse up . Could also change weapon with a short click.
- Simply change the diamond color with another shot.
- Use different shape for orbs in addition to color.
- Speed up the character
Overall the game is pretty well done, the downside are mainly due to controls. With simpler controls, the exploration of the game is easier and the lack of a tutorial can even be armless.
Keep up the good work !