Rabi-Ribi is a 2D side-scrolling metroidvania developed by CreSpirit/GemaYue, released in 2016 for PC. I originally picked it up during a sale because the colorful art style caught my eye, and I did not expect much beyond that. It ended up being a genuinely solid and memorable game.
The story follows Erina, a pet rabbit who is mysteriously transformed into a human girl. Together with Ribbon, a tiny fairy she meets early on, Erina sets out to uncover why she has taken human form and what exactly is happening on Rabi Rabi Island.

As she travels, Erina constantly finds herself pursued by the rabbit-obsessed UPRPRC (Usagi Pero Pero Club) and various other enemies. There is much more going on beneath the surface of the island, and Erina gradually uncovers mystery after mystery. The game also includes a DLC that adds extra story content.
The plot itself is not groundbreaking and even the spoiler-sensitive elements are not likely to shock anyone, but it serves its purpose well. It introduces the world, gives you characters to care about and supports the gameplay rather than overshadowing it.
Erina herself is incredibly cute and charming, and the game is filled with likable characters. You meet people like Miru, the sleepy girl who gives you special items in the post-game, the friendly shopkeeper Miriam, Saya and many others. It is very easy to form attachments to the cast.
Where the game truly shines is the gameplay. Rabi-Ribi is a well-crafted metroidvania with noticeable bullet hell elements during boss fights. Erina can attack enemies at close range using her Piko Hammer, while Ribbon provides various projectile attacks for long-range combat.
There are tons of items hidden throughout the island that enhance both Erina and Ribbon, and, as is tradition with metroidvanias, exploration is nonlinear. You can choose where to go, what to attempt first and what areas to postpone until you find the right tools or upgrades.
Even someone like me, who is not particularly experienced with this type of game, was able to navigate the maps without much trouble. The exploration offers many possible paths, yet it never becomes overwhelming or confusing, and I rarely felt lost despite the freedom the game gives you.

I highly recommend giving this game a try next time you see it on sale. It has cute characters, fun and responsive gameplay, and a reasonable length that will not demand an overwhelming time commitment.