Beat em ups are relatives to fighting games, this would specifically be a relative to platform fighting games. You're in single screen levels, kinda old arcade game style too. You start off without special moves but learn them quickly throughout the levels, simple 4 directional inputs Smash style, but you can customize them. Some of them are really fun, getting Innocent Pendulum to hit a bunch of enemies at once while slamming one other enemy down is great. knocking an enemy into a row of enemies with the basic forward kick is great. The story is pretty short but there is an endurance mode. Has that real doujin spirit.

This is definitely a predecessor to the PS3 onward era Sony Cinematic Game, but whereas those suffer from being overly safe, this suffers from having experimental ideas that haven't really been refined further.
This was midway into the PS2 lifespan, the right stick still hadn't been fully embraced as being only the camera control/aim stick yet, so this game tries to make it the primary method of fighting, similar to Death by Degrees. This style gives lots of control over which direction you attack in, but also limits how much variety your attacks have. The speed you hit the right stick in a direction changes your attack, but this is something hard to actually get used to. Also got my thumb tired quite a bit. There's grabs and countering too. I found that countering often hit enemies just out of reach to continue combos, so that's annoying. I feel that the most obvious way to improve a game like this would be to add mild tracking to attacks. There's shooting segments too, these are pretty basic cause you don't even really aim, you just point the stick in a direction and it auto aims for you to shoot. Targeting enemies and objects is a separate button so that's annoying. There's actually a cover system too but you can only use it for dodging, no aiming from cover. Lots of segments like outrun explosions, stealth, and dodging snipers exist too for quick diversions.
The story is "Hong Kong action movie in video game form" more than anything else. Cory Yuen worked on the choreography of the motion capture. Lots of nods to Jet Li films, like a fight in a room with leaking gas where you have to constantly keep your oxygen up. Even the main menu has a bit of a DVD vibe, the level select screen looks the same way a DVD would make a scene select screen and there's behind the scenes interviews. Jet Li seems so happy to try motion capturing. Costumes you unlock for completing the game are neat

This is a rougelite FPS that strips things down to a very simple form. You have your weapon in your left hand and you have your wave attack with your right hand. You get random upgrades at the end of levels, but the levels are always consistent so there's room for memorization instead of being solely at the mercy of rng. My first successful run took about 20 minutes. There’s also a difficulty where you just start with 4 cards and never get any more.
Aside from the lowest difficulty, you have constantly decreasing health and killing enemies restores your health. There’s no score aside from the timer, so you can avoid them if your health is full. Most of the weapons are straightforward FPS weapon archetypes, though there is a spread gun made from the head of a girl that also lowers your HP when you reload. I’ve never gotten it to work though. The individual levels are more fun than the boss fights that are pretty boring unfortunately. It’s simple and a bit unpolished, but there’s charm to that. There’s not a whole lot to the game, but it’s good enough that I don’t mind coming back to it. Plus it’s only 5 dollars.
There’s lots of references to contemporary Japanese trends and culture, main girl has Jirai Kei fashion, one of the weapons is a Circle Crasher. Someone with more knowledge of Japanese culture may appreciate this more.
The easiest difficulty is “For CUTE Girls” and disables the constantly ticking health. Perhaps it’s wrong to make easy mode for girls, but perhaps the creator recognizes that cute girls do not deserve death.