One of my favorite games from last year was this Japanese doujin shmup called BulletGarden, created by a demoscene artist under the name StudioTwilight.
(As an aside, I really love this song and music video by this artist)
BulletGarden is, at its simplest, a bite-sized shmup where your weapons fire automatically to the beat. The weapons and enemies contribute individual melodies over the different backing tracks, and changing weapons changes the sounds, so as you play the song evolves.
Since you switch weapons so often, there's a HUGE variety with impressively different effects or looks. For example, cats which leave pawprints, or bombs which rain from the top of the screen, or penguins that slide forward and loop, or dolphins that spit bubble rings (I promise not all the weapons are animal-based).
You can play a mission mode comprised of fixed objectives with determined loadouts, or an endless score attack mode using loadouts you customize yourself. I really love the missions, because most of them force you to play with odd loadouts and difficult objectives, introducing you to each weapon's strengths while also quickly demonstrating their weaknesses.
There's a gachapon element where you earn the weapons for your customized loadout by doing pulls (the "planter") using a meta-currency you obtain from defeated enemies. There's no monetization model, this is purely for if you want to tackle the arcade mode with a preset loadout, so it ends up feeling more fun than annoying. If you don't care, you can always just play full random, which will give you any weapon, even ones you haven't unlocked.
It flew under most people's radar, but if you have any interest in action game design, you owe it to yourself to play this game.






