Haiku (name unexplained) is a metroidvania with many similarities / references to Hollow Knight and Metroid. You gain new abilities and explore a large room based map, backtracking to new areas once you can do new things like explode or double jump. It has a great pixel art style, and the atmosphere and music are really well done. I believe it's made by a single person too, and it's extremely polished for that. Similarities to Hollow Knight don't end at the gameplay; there's also the combat, sockets (Charms), platforming and also the story / location (descending into a world of machines driven mad by a virus). A solid, short experience for fans of the genre.