Ah fuck, you're right - NSW only in EU. That sucks... Omega Fighter isn't just a classic buzz STG, it's also one of the best ACA values alongside Salamander (you get three very different versions of the game in each).
Seems there's a ton of 2017-19 stuff like that, Switch-only in EU.
I see Thunder Dragon 2 is there, at least. Definitely consider that one if you want an archetypally easy to pick up, hard to put away vert STG. It gets wicked hard eventually, but the difficulty curve is pretty approachable. Lots of bombs, make sure to use 'em! I gather from your av that you're familiar with Sonic Wings/Aero Fighters - TD2's overall feel is kinda like those and earlier Psikyo, very approachable albeit not to be taken lightly.
On that note, I think you mentioned looking for introductory STGs? Besides XEXEX, as mentioned, I would definitely go with X-Multiply. Only caveat is what sorts of STG you prefer; these are both terrain-heavy horizontals, as pioneered by Konami and perfected by IREM. Both have generous ships - fast, powerful, with small hitboxes and fantastically tactile Option mechanics - balanced against some tricky stage designs.
If you want something more in line with Toaplan (fast aimed shots) or CAVE (the archetypal bullet hell), you're probably better off making a JP account and getting into ShotTriggers, which tend to have really nice Beginner modes.
Also, I think Eschatos got an EU release? That one includes beautiful ports of Judgement Silversword and Cardinal Sins. JSS is distilled excellence, you won't go wrong with that one. Generous with its shield, fiendishly compulsive with the scoring requiring you to aggressively battering-ram enemies and bullets with it, rather than reserving it for defense.
If PC is an option for you, get Siter Skain's
Kamui. There isn't a better-balanced example of arcade intensity and console generosity, imo. Technically a doujin title, but easily on par with its professional inspirations from Taito and Raizing, packing a raucously destructive yet electrifyingly techno-ethereal style entirely its own. Shearing massive targets in half with the GodLazor before blasting them to burning shrapnel with the lockon HellRayzor never gets old.
Should go for cheap on Steam, possibly bundled with its companion STGs RefleX and Alltynex 2nd, which are both cool, but Kamui's the one you want.