Ah yes, finally, what I didn't even know I needed is here. At first, I was like "oh, some random Metroid mod that probably isn't very good", then I saw Scooterboot behind this and I knew this was going to be good. I actually recall the 1.2 tAPI mod of this, although very vaguely. Metroid being one of my favorite (if not the favorite) of Nintendo's franchises, I'm in glee with playing this mod. I loaded myself a Metroid wave bank and did a full playthrough of this mod with vanilla, this mod's, Fargo's, and JoostMod's bosses. I really like the ruins generated. Boss fight was pretty good in there too. Leaves me with a thirst for more structures, perhaps even entire sub worlds. Exploring Dark Aether, now that would be something. Err... please don't take that as undue pressure, I know suggestions can come off like that at times. Dark Aether probably has been considered during development.
As for suggestions, maybe defeating a boss for the first time could drop missile expansions? I think the very first game did that. Well, not nearly as much given a lot more bosses in Terraria. Perhaps the metal detector could pick up Metroid goodies as well? After a lot of randomly teleporting and exploring around a small world, I managed to get about 25 or so missile expansions. I don't know if only exactly 50 generates per world. The missile expansions do give a reason to explore around where normally I don't do nearly as much after the usual mining and life crystal hunts. Perhaps there could be grapple beam upgrades, mainly for length? I find it really fun to use when I get it working well, since you can build up speed with it.
For some reason, Serris causes me to crash. I think it happens either after hitting him or when he becomes possible to hit. I'm playing on tModLoader 64 bit with 100+ mods loaded (most are pretty small stuff), so I feel posting a mod list wouldn't be helpful. I could try to narrow it down some other time, but I'm well aware just how unstable this setup can be.
I do like the Terraria infusions of Metroid items like the celestial pillar fragments. Hmm... I wonder if we're getting Solar Flare and Stardust suits at some point. Speaking of armor, the current two armor paths seem to have not much in the way of differences. Perhaps they could take on the traits of their fragments, like say, tanky Solar Flare suit, or a Stardust Metroid to help you with the Stardust suit. It's certainly a different take then making a celestial fragment exclusive just to Hunter class.
Given how there's Chozite, I wonder if there would be more non-Hunter class Metroid style items, almost like how the vanilla classes' take would be on being put into Metroid setting.
Since I dealt with the Metroid bosses the Metroid way, in latter playthroughs, I'm interested in how I'll deal with them the Terraria ways like summoner. Another time, could even do a Hunter playthrough with more mods like Thorium.