It's a good place to farm spawners for use with other mods (e.g. EnderIO, Draconic Evolution). What I do hate though is that when you make the portal with the staff, it's made from unbreakable blocks so you can't remove it if you decide you don't want it there anymore.
There are actually six types of rooms:
- The room that you spawn in - lit up and empty, except for the return portal.
- Four chests with spawners on top. Dropper with the key is hidden in the centre.
- Obsidian-encased spawners. Four pillars near the corners, with a block encased in obsidian in each corner. Two spawners, one chest, and a dropper with the key.
- Library with bookshelves, loot chests, etc. (you get one book for each shelf you break).
- Wither boss. There is no dropper - you must kill the wither to get a key. Note that you can actually get extra keys by summoning your own Withers in the dungeons.
- Guardian boss (right click the spawner to spawn the boss, which is essentially a giant iron golem). Similar to the Wither, you must kill the boss for your next key.
I do agree that the mod maker should add more variety. Stuff like:
- The "booby trap" floor blocks which hurt you when you walk on them are more annoying than anything. It would be better if they were replaced with, say, actual spike traps where spikes extend into the space above them periodically, doing lots of damage if you're standing on them. The random arrangement is also annoying - maybe in some cases it's okay but an ordered arrangement would be nice to see as well.
- More kinds of traps:
- Maybe you open the door and see an empty room with nothing but the dropper and a few loot chests. You walk into the room and suddenly the door behind you closes, the loot/dropper vanish and lots of mobs begin spawning, and you have to kill all the mobs. Once you kill the mobs, the loot and dropper reappear and the door reopens.
- Stuff falling from above (e.g. creepers, TNT, lava, gravel). Either automatic or set off by a pressure plate or tripwire (the latter would be harder to survive/escape once triggered).
- Anything else you can think of (as long as the trap isn't both unavoidable and inescapable).
- Have rooms with a variety of shapes and sizes. Maybe a big room, or a long, winding, hallway-type room. Multiple floors would be cool too.
- Another trap would be to have a room where the floor disappears and you fall into a lower room. If you don't have blocks or another way to get back up, you'll have to dungeon crawl until you find a way back to the rooms you've cleared. Maybe close the floor (now a ceiling) after you fall in to be even more evil.
- A long room where once you walk a certain distance into the room, you hear a noise and the blocks nearest where you entered start falling into the Void. You have to run to the other end of the room (which might also contain mobs and stuff). At the other end, the blocks there don't fall into the Void and there's a single dropper with the next key and one or more doors to continue on to. The player can either continue and try to find their way back, or if they have blocks they can build a bridge back to where they entered (a clever player could place their own blocks as a platform before blocks start falling into the Void, too).
- More mobs, such as Nether mobs or even adding more unique mobs, or detecting other installed mods and using their mobs (e.g. Twilight Forest mobs).
I do think the mod maker intends to add more stuff since, yes, the mod is pretty new.