I am disappointed with Deep Dungeon

[Yukiko]

(..) it's supposed to be really hard to reach 200, (..)

Thats not how a dungeoncrawler works.
While it is true, that the monsters getting stronger with each floor, it doesnt mean that it will become harder!
The keypoint in dungeoncrawler games is that you may run out of items or armor/weapons.
Its not the problem of rushing too fast through it, but could be because of RNG loot.
While on the first half of floors you will get higher chance of good gear (because you are not at max level where you need the best of the best stuff) the second half becomes harder because you will need to flee from some enemies until you get special items or you catch up with level. Speaking of level: It is common to outlevel enemies if you cant pass a floor, thats why you are motivated to run the same again and again because leveling up (or getting better gear, or to stock up items) to finally pass the floor...
Mostly it is designed, that you can power up on the fly without repeating the same floors 100 times.
I have seen bad dungeoncrawlers where you had to level in floor 1-10 for 200 times before you could survive floor 11-20...
While in good dungeoncrawlers you can go through floor 1-10 getting more or less usefull items/gear and with use of them you can pass floor 11-20, depending how lucky you are with RNG loot, you can reach the last level, for those who are unlucky, there are checkpoints where they can save the items and stock up to prepare for the next floors... still, there are dungeoncrawlers i liked most who had a very good balancing where you just had one life and dead means DEAD.

Just my opinion, but currently it is not a dungeon crawler (compared with wizardry)


To finish my posting: I like what was said here:

(..) The ability for SE to not understand the difference between fun and tedious has become astounding; this is further exemplified by talks of this dungeon receiving and additional 150 floors in the future. The idea of this dungeon being 300% longer makes me want to drive my head through my wall.

[Maxipep]

It looks like the Dev's got fed up with it too, I think this was the first patch released with known issues. Mind you it is super boring, but I'm sure to it's pretty amazing to some people which is cool. They can't please all of us all the time. All you can do is try these things and if you don't like it move on.