IMHO the exp required to next level needs to be toned down.
Or atleast make it so that only 1 energy used per exp get, regardless how many exp you get.
The idea is so that when someone opens the game after their energy is full, they can spend it on 24 dungeon runs of their choice. It should help a bit with the massive TNL jump.
NGL, even with macro to auto enter dungeon and auto tap looping it can be awhile. And that's just from Level 26 to 27
Also, the description for "Assault Machine" sounds kinda misleading. The way it's phrased right now makes people assume that once you learnt it you can press the screen and it will attack like you repeatedly tap, but instead it simply makes the 1 attack per second do 100% damage.