Listen There is 2 way you can play this game
1. Casualy
Play a couple of run, figure out how the characters works. Pick up things you have not seen before, and try not do die. Maybe do some challanges to spice things up, and learn of interesting synergies.
2. Completions is
DO THE FIRST 6 FLOORS UNDER 20 MINUTES, AND THE FIRST 8 IN UNDER 30. DON'T PICK UP DEVIL DEAL, ALWAYS GO FOR ANGELS (once you unlock them of course) TO GET THE KEYS YOU NEED, THEN RUN THE 50% CHANCE TO GO FURTHER AFTER BEATING THAT BOSS
In all seriousness this game is great. It has kinda steep learning curve at the start, and expect to die with out beating Mom your first dozen tries. After that, and learning synergies and what items are good or bads (with a little help from the wiki) you will be flying through this game in no time

This is a pretty neat card based battler
the animation and art style is very cute, and the idle animations are also a highlight, and seeing the easter eggs in characters designs is a good ol' time
I am still pretty early in it, but the plot is silly and fun, which suits the game style.
the music is very good, very jazzy, or funky, i don't know music terms. I like the effect of it slowing down when you pause, its a really nice touch
My main grip is some of the wording of cards is a bit weird, and can be misinterpreted when you first get them, and not fully seeing what upgrades character can mess with deck making (there's a a card that gives you 3 armour depending on how many cards you have in hand, and you get it when you hold 5, and now i am getting 8, and i think i can get more hand size) but that just means i can replay it and make a different build next time
also the winning a fight with full health achievement is not working right now, but that might just be me

all in in all, a pretty solid, simple card battler, with stylistic art, fun writing, Solid gameplay, and a funky sound track, it well worth your time. And at $15 Australaian, its well worth your money