I'm kind of on the fence about picking it up. It's my favorite Cave Shmup (although both Mushihimesama games are catching up) yes BUT it's also on PS4 and for reasons I made an entire thread about I've scaled back on PS4 games (although I did just pick up the Zero Escape games)
I know M2 did the port so it's solid from that perspective. I know it has a few new modes but I don't know anything about them, and I know it has some arranged music.
I have the PS3 version and thought I could get by with that but Deathtiny does seem like the definitive version.