An interesting little game! It's a bit shallow and short, but it doesn't overstay its welcome and keeps things interesting and novel by switching up the rules with each wave. There are some frustrating bits like how difficult it is to ricochet shots back at the sun since there's so little room to work with, but for the most part the game is exciting and fun thanks to the explosive feedback/effects and intuitive arcade gameplay.
That said, the design of the game was pretty questionable at times. I expected the rock wave to require you to shoot the rocks down quickly to prevent the sun from absorbing them and gain power: that way you're forced to play effectively and risky to keep all the rocks away. But no, you can just leisurely take your time and shoot the rocks at your own pace, killing any sort of excitement until you reach the required 100 points. It just made it a bit confusing because you'd think the game would always focus on you vs the sun, but when it comes to the rocks...why are you getting points for shooting them? The other waves made more sense since it involved you fighting back. Also, why does the game even have a high score system when getting points is required to reach certain wave progression at 100, 200 and 300: doesn't that just mean everyone who beats the game ends up with the high score in the end, unless perhaps the sun's final phase health bar has some wiggle room?
Overall though, it was quite the memorable experience due to the interesting wave progression that gets you to the final showdown: a nice, short and sweet story!