I got this game from the Groupees "Give Back" bundle for free, and was pleasantly surprised with the gameplay.
If you like music generation, smooth/slower bullet hell-style gameplay (lots of dodging), and challenging gameplay against nice backdrops, you will enjoy this game.
The aesthetics are simple but nice - different-colored tracers fly toward you in varying patterns, all with changing backgrounds that are serene and minimalistic. The sounds and music are great - different sounds occur whenever you get the projectiles to hit each other.
The controls are very easy and simple - you just move around with your mouse. One thing to now, however, is that the your cursor speed is purposely slow, as the game encourages you to relax and use smooth versus frantic movements. Since I use extreme sensitivity on my mouse, it was a bit of a change having to actually move my mouse across the entirety of my mouse pad (my sensitivity + acceleration is so high I just have to flick my wrist to cover any area of my screen). The learning curve is pretty minimal, as you only have to dodge the end points of projectiles (you can cross over any other part of the projectile). The patterns in the different levels keeps the game challenging, refreshing, and fun.
I've enjoyed playing this game quite a bit. There are 3 game modes: survival (game over after getting hit), score attack (3 lives), and endless (it literally goes on forever). BE WARNED: there is no menu/options, and if you accidentally press ESC at any point during gameplay, it will take you to the main menu and you must start all over again.
If you are interested in this type of gameplay, you will enjoy Borealis.
DJSF @DJSF's Rogue Reviews