Well I just ran Malatina's Dungeon Game, so I figured I would share my thoughts on how to complete it. According the the dialog from Malatina AFTER you complete your run, if you manage to dig up all the squares and open all the chests 30 times, she will present you with a special award.
To enter the dungeon
Malatina is in Varana's Central Square, standing on a ball around the fountain. Simply talk to her and she will provide you entrance into the Dungeon Room. To take the quest, you must have 30 Bernidine Tokens on hand, and you can only take it once per day.
Personally, I would suggest doing the Valentine's Day quest right before this for the small buff. If you can, get someone to buff you with a long term buff as well, Amplified Attack and Enhanced Grace of Life come to mind.
Once you have accepted her challenge, she will teleport you into her zone. Her servant is standing in front of the doors, and the timer will not start until you talk to him and request entry. That means you can do any last minute buffs/meditations before you get busy.
Once the doors open, the game begins.
1. Clear a working space
First off, the layout is basically a large chess board. Under each tile is either a treasure chest, monster, or bomb. At the edges there are some energy looking pilons that will zap you every few seconds. To dig up a tile, just click on it as you would a resource. Like harvesting resources, if you are damaged it will halt the timer and force you to begin again, so before you begin digging, clear out a space free from the zaps by clearing off a section of board. For example:
[INDENT]xxxxxx
x----x
x----x
x----x
x----x
xxxxxx[/INDENT]
This represents the board, with all the x's being an energy pilon. To avoid getting zapped, immediately destroy one of the corner pilons, then work your way in on both sides. So after demolishing the first 5 energy pilons, you would have an open digging field as so...
[INDENT]xxxxxx
x----x
x----x
0----x
00---x
000xxx[/INDENT]
This means all of the squares marked with a 0 should be safe to dig in without getting zapped. To continue, just work your way around the board, clearing off the energy pilons. For example:
[INDENT]000xxx
000--x
000--x
000--x
000--x
000xxx[/INDENT]
In the scenario, you've destroyed half of the pilons on one side, so exactly half of the board is safe to use. Apparently, the pilons shoot rays only from pilon to pilon, so you can clear them out in strange ways to maxmize space.
For my next attempt, this is the order of pilon clearing/digging I plan to use. Feel free to post your own attempts/suggestions:
[INDENT]1. Destroy Pilons
xxxxxx
9----x
8----x
7----x
6----x
12345x[/INDENT]
[INDENT]Dig Tiles
xxxxxx
1----x
23---x
456--x
789(10)-x
(11)(12)(13)(14)(15)x[/INDENT]
Then I will destroy the pilons on the right side (* shows a cleared/dug tile):
[INDENT]xxxxxx
*----5
**---4
***--3
****-2
*****1[/INDENT]
Then clear all the open tiles, except for the northern wall.
[INDENT]xxxxxx
******
******
******
******
******[/INDENT]
Now this next part is speculation, but I think it might be quicker to time your digs on the last N wall of pilons with the energy bursts, so that you dig up the tile without killing the pilon or getting zapped. If possible, it will save you some time from having to kill the pilons by just ignoring their bursts, which should only affect you if you are actually standing on the N row of tiles when it happens. If this doesnt work, then obviously you will have to destroy the pilons on the N side too, and dig under them for their chest/loot/monsters.
2. Bring the best potions you can use
Remember, this is a TIMED event. You do not have time to sit there and meditate to regain HP/Mana, so bring the best potions you can afford, and use them up religiously.
3. Concentrate on high damage in as little time as possible
I would highly suggest that low DPS dealers grab the highest damage combo/quickest damage combo they can find, as this is all about clearing the board as quickly as possible. As a K/P, I am used to the slow and steady approach to clearing out mobs. That does NOT work here, you need to maximize damage and use potions to clear through as quickly as possible.
4. Watch out for bombs
The small bombs only have a 2 tile radius (1 excluding the bomb itself). Just step back and you'll be fine.
The medium bombs have a 3 tiles radius, maybe 4. If you have the room, back off immediately. If not, just take it.
I havent seen a large bomb yet, but I assume there is no safe part for it. Just hit a potion and keep going.
Well that's it so far. When i first got in I wasn't sure what to do, and consequently I only opened 3/4's of the squares on my first try. But I am confident it is possible to get them all if you clear your space properly, watch out for bombs, and have a ready supply of potions.
Once we have a bit more input from other users, I will add screenshots and a more complete walk thru. If you have an alternative strategy to share, feel free to post it as a reply and I will include it.
Good Luck!
Talanithus