Hi there! I've tried your demo, and I liked it!
They controls were good (i used keyboard), and it ran without any problem/lagging.
Got to score 803, and by that time it got a bit repetitive, so a few new enemies could help with that (maybe some power ups).
The rage mode could use some changes. When it activates, enemies run away in different directions and it's hard to hit them (vs them coming towards you). Maybe have them freeze in fear, wipe all enemies on screen, or make you invincible for a few secs.
Good job!