sometimes it's just so fast/so many enemies
Agreed. However, it's as-designed.
You do literally have to go through at least one of those rooms. The rooms are not completely random, there's a 10% probability of guards-only room, and the room before the boss room is always guards only (unless it's a shop). Since the game will probably have 5 levels on the first playthrough (you unlock levels 6 and 7 when you complete the 5th level for the first time and unlock the "hard mode") you're already deep in the game and the difficulty has to ramp up.
I don't have time to cross a room, bomb a door, and escape
Use Ice Hammer to buy some time, or Rogue Sword and just sneak through.
I watched some video a couple of days ago and read some player comments on Enter the Gungeon vs The Binding of Isaac and this made me think about the game a little bit. I feel like the game should be hard, but you should be powerful. So, I think I will revert some stuff I nerfed recently. For example, I'm changing back the Ice Hammer to be rage based. Since Infinite Rage potion is removed, you can never have too much freezing
I'll probably just shorten the default freeze time a little bit, but it should make it more fun to play.
I'm also considering to rework the rune system, have the Damage Rune (melee,archery,magic) and Range Rune (magic,ranged) combined and use the extra runes to power up some other aspects of the weapon (elemental damage, special effect duration, etc.). Not still sure how would that work, but I'd like to reduce number of useless items you might find.
Also, adding more potions with positive effects (currently it's around 55% good, 45% bad ratio) would make it less risky to drink potions and the players would be able to power up before they get into tough areas.
Still, I'm beating the game about 50% of the time with a mage, and around 30% of the time with Archer and a Knight which I feel is a good difficulty range I want to have. Currently I want the game to be more like Spelunky in that regard.