Imo they both kinda suck, it's like if the effort they put into making those games were just nothing rather than make it look promising enough to catch the public's eye. Ktk3 looks really good, and DoDonPachi ost is amazing as always, but it never amused me the idea of, getting the rooms of other fangames and make it harder and call that your game. And the bosses are all kinda the same thing, RNG based bullet hell. Ktk3 is fun, but at the same time it's just bad level design. Happil 2 did the same thing, except it was way more stupid and a billion times harder, for no reason.
But that's how I see it, I know there are people out there that are absolute masochists and love playing hard-ass needle games.