Beat the game at 4:04 by destroying the enemy base. There are some issues I would like to present:
- Most of the audio is repetitive. You may want to introduce pitch variation to reduce the effect.
- The gun gets louder each time it gets upgraded. By the time I reached max level, it was far too loud.
- The gun fires as fast as you can press so it makes it easy to cheese the enemy base by just clicking really fast.
- The movement animation for the player character seems to have some artifacts near the feet.
- the enemies died and exploded with look like particle systems. The particles should fade over their life so they don't seem to disappear instantly.
Besides these issues, I would like to say the game could still be very good if some improvements are made.