It's a solid and well presented game. For the casual experience it will be quite good.
However, the player is meant to pursue ACE rank in all missions. Normal mode was decent but NG+ is where the game reveals it's problems with balance and mechanics.
For a short action game, it's not as fine-tuned as it needs to be. Inconsistency is the key issue. ACE rank can be too dependent on RNG too often. Feels like luck of spawns and patterns over your skill as a pilot. You need high amounts of enemies killed quickly to score, but it just doesn't give you that. Mechanical inconsistency too like timings of hits and evades. Two examples: dash mod is too wide that you kill ships without being close to touching them. And even the final final boss scripted 1st attack has a bizarre delay on it where you dodge, it's not even on screen anymore, and it kills you.
Weird magnet effects and collision detection problems due to mechanics or wonky hitboxes.
After getting ACE ranks in all missions on both difficulties, I cannot shake how miserable that experience was. Clearly there are mechanical problems and balance issues. Some, but still TOO many, levels in particular seem to have never been tested by the developers because no metric on earth can justify how horrible they were to ACE. Some were fun indeed, but all were overshadowed by the depth of frustration due to the bad.
It started nice, but became more frustrating than fun. Practically work. Maybe some of my experience was impacted in that I used a controller or my computer has high FPS.
It was a nice little secret on NG+ presented well. Music and Art were good. But the gameplay is what matters most and the flaws I encountered really ruined it on NG+.
Arcade mode is a neat addition but after the negative time I had ACEing, I don't care about it. I'm left with no happy memories of the game and it completely soured the experience.