The game was addicting and enjoyable to play. The best part is the music and smoothness. The power-ups were very welcoming as it made ranking up much more enjoyable. This game was incredibly addicting, taking at least half an hour of my time.
The worst part of the game was the repetitiveness. Flur never changed no matter how many Spritelings you collected or ranks achieved. The only reward for ranking up was the achievements, an thus left me unsatisfied. The Spritelings were repetitive with the biggest change being that some may hurt you. The groups varied only slightly from each other with the exception of the DNA strand, Pulsar, and Helia; while every other group had simply a few more orbiters. The Spritelings also had incredible speeds whenever Flur sped up and thus caused many deaths. The background never changed and seemed out of place; the Sprites and Flur were bright and fluid while the background was dark, grey, and still. The achievements were also highly repetitive.
Improvements I would make is to make Flur dynamic, with each passing rank Flur actually changing and improving. My suggestion would be to have the Flur in the menu be the final product while the Flur you play as start out as a Spriteling. Flur could then grow wings, then antennae, then have a small body, etc. Ranking up should also have greater rewards such as increased speed, vision, etc. The background also needs to be more dynamic, as seeing the same dreary background really brings down the brightness of the characters, possibly having the background become more colorful and life-filled as Flur improved. The dangerous Spritelings should aslo have been a color that contrasted well with the Green Spritelings, as when the game becomes more crowded it becomes difficult to spot what's orbiting and what's not.
In summary, this game is addictive but suffers from repetiveness. The music and sound effects were enjoyable. However, ranking up was not very rewarding, Spritelings only slightly changed, and the background was out of place.