Osorubeshi! Xaklogian - Hard - ALL - 3.346.120pts
This looks like an MSX game, scrolls like an MSX game, bleepbloops like an MSX game...but it's actually a PC doujin homage to the microcomputer, and a pretty fun game in its own right too! Hectic pacing, lots of tiles to uncover and destroy, enjoyable music, short and sweet, and with some interesting ideas and setpieces in each stage. I don't know if the MSX could actually run a game exactly like this but I am not a stickler for accuracy when it comes to these homages and especially if cheating the limitations makes the game more fun.
I heard about it back when it released in 2015 and played it a bit. I enjoyed it but didn't push it much. That is now fixed as I grabbed myself that Hard mode clear!
There is also an extra stage you can play by pressing the K button 8 times on the title screen, and that one is a lil' tricky.