EDIT:
I wrote this review when i had 46 gameplay hours and not fully completed and now its has all four charcters and endless boss mode that playable until 60-75 floors unless you use glitches.
Here an update of my viewing of the game

pros:
+challenging boss battles.
+replayability value.
+balanced mechanics.
+four characters with different play styles.
+different ways of decemtiting enemies
+Interactions between heros and bosses are wll thoughted.
+Its has achievements.
+Endless boss mode to test your skills.
+catchy soundtracks.

cons:
-no in-game guide for quests since the story path is not clear.* *for the first gameplay only
-opening crystal and button doors can be tedious.*
-you have to backtrack alot to finish the game 100%.
-Endless boss mode is not that endless and is breakable.

EDIT: I wrote this review when i had 46 gameplay hours and not fully completed and now its has all four charcters and endless boss mode that playable until 60-75 floors unless you use glitches. Here an update of my viewing of the game pros: +challenging boss battles. +replayability value. +balanced mechanics. +four characters with different play styles. +different ways of decemtiting enemies +Interactions between heros and bosses are wll thoughted. +Its has achievements. +Endless boss mode to test your skills. +catchy soundtracks. cons: -no in-game guide for quests since the story path is not clear.* *for the first gameplay only -opening crystal and button doors can be tedious.* -you have to backtrack alot to finish the game 100%. -Endless boss mode is not that endless and is breakable.