Two interesting projects we've not covered here before are UltraStar Deluxe and the newer UltraStar Play, both open source games aimed at karaoke fans. You've likely somewhere heard of SingStar, an exclusive PlayStation series. Sadly, it was shut and so it's mostly lost. Thankfully though, as usual, open source to the rescue!
UltraStar Deluxe has been going for a while now, with an aim to create a similar experience. It's been going strong but there hasn't been a release of it since 2020 and going by the GitHub page, not much development activity for the last year either.
Another more recent project appearing is UltraStar Play, which we're told is "the youngest of UltraStar games, currently in development and available for desktop (including Linux) and mobile (Android already available, iOS planned)" and that in response to SingStar shutting "UltraStar Play fills this gap by allowing everyone to create their own sing-along version of songs. And it removes the need to buy USB-microphones via the Companion App such that you can use a regular smartphone as mic (see the Companion App).".
Note: while UltraStar Play is open source, the project itself relies on the proprietary Unity game engine.
It's not finished but it's perfectly usable and should be fun enough to get a party going. With the UltraStar Play Companion, you only need a phone to use as your microphone so it's quite cleverly thought-out.