Ginga Force and Natsuki Chronicles, two sides of the same story released six years apart and spiritual successors to my second all-time favorite shmup, Eschatos, are on sale for the next 10 days in a seriously-way-too-cheap bundle on Steam.
A mere $7.18 USD gets you two of the most well-crafted shooting experiences of the last decade, set to some of Yousuke Yasui's (plus some SuperSweep alumni guests') finest tracks.
Ginga Force is vertical, like Eschatos before it, and Natsuki Chronicles is horizontal. They both build on their predecessor's simple shooting mechanics by adding shopping and weapon customization, not unlike Capcom's U.N. Squadron/U.S. Navy games. Play through stages earning points to spend on new main weapons, sub weapons, option bits and other gimmicks, then play the stages again aiming for higher scores (or simply survivability) with your new equipment. My biggest gripe with these games is that they both lean hard into the "story is delivered by constantly jabbering anime heads while you play" like the rest of the genre has the past few years, but thankfully the voices can be turned down.
M-KAI, the main programmer of these games, has far-reaching history in the genre that includes such system-breaking games as Judgement Silversword (WonderSwan), Kanzen Kouryaku Kyokugen (MSX), and Pleasure Hearts (MSX) (flickering/flashing warnings for all those video links). If you have any passing interest in the genre, you owe it to yourself to check out at least one of the games I've mentioned in this post.
If I had made a 25 games to know me image, this would be in the top row
Also not to be missed is this bundle for Ginga Force and Natsuki's granddaddy, which gets you the game, Yousuke Yasui's original soundtrack in FLAC (with a bonus Ryo Yonemitsu arrangement), and a PC port of the great-granddaddy mentioned in the op, Judgement Silversword.