Genocide has never been so fun. A bit repetitive, but fun. There were only a couple unique bosses with the vast majority just being metroids that for the most part are extremely easy to kill, but the unique ones that were there were really cool fights. The map was pretty well designed thought and I love that they added a sort of fast travel system even if it's only accessible towards the later parts of the game, and the movement feels nicer than the other metroid games I've played so far. The controls were also simple to change to make it however you want, including options to make it more like Super Metroid or more like Zero Mission.

Being someone who likes to 100% games, I've found some very cleverly hidden expansions. I prefer cleverly hidden to just overly difficult like some of the ones in Zero Mission. To me it feels more rewarding to get something that is well hidden and maybe just takes doing a trick of low-moderate difficulty, than it does to finally get something that takes long and super precise tricks and aren't easily reset. That is more relief that I don't have to keep trying and reloading save states than an actual feeling of accomplishment.

Overall, a great Metroid game. It's free and a whole lot of fun to play through. Definitely worth playing.