Draft:Shiren 5 2020:Explosion Rocks

Explosion Rocks is a minigame in Shiren 5. You can read what that means and entails on the Shiren 5 Locations page. It is a Shiren take on the classic logic game of Minesweeper.

Gaining Access

You can launch Explosion Rocks from the Dungeon Center in Nekomaneki Village. Access is not restricted; you can play as soon as you can reach the Dungeon Center.

Unique Features

Location Type

All ancillary content in Shiren 5 can be categorized as either a puzzle set or a bonus dungeon. Explosion Rocks has elements of both but doesn't fit easily into either category. The distinction between location types is likely artificial, not part of the game model itself. The code probably allows designers to configure things like "should I destroy all items and gitan the player is holding when I start this location" and "should I enable special rule X in this location" for each of the locations in the game. So, while the model probably allows for a large variety of unusual combinations of settings, the game designers have tended to configure locations in two main ways, either as puzzle sets or as bonus dungeons. But much like light defies easy categorization as a particle or as a wave, Explosion Rocks defies easy categorization as a puzzle set or as a bonus dungeon.

It's like a puzzle set because:

• There are a group of related "puzzles" you can launch from the same menu. (That is, you can choose from 3 difficulty levels.)
• You can restart or quit anytime you like.
• You are prompted to quit early (keeping any inventory you've accumulated) every time you change floors. This is not true of any other puzzle set or bonus dungeon, but feels more "puzzle-y".
• You can fail but you can't die in the same way as in a dungeon; starting Explosion Rocks doesn't count as a "run", and leaving it doesn't reset your opportunities in the Starting Villages.
• It's clearly based on Minesweeper, which gives it a strong "puzzle-y" feeling.
• There are no expert badges available.

It's like a bonus dungeon because:

• For most other puzzle sets, puzzles tend to be 1 floor each, but each difficulty of Explosion Rocks is 5 floors long.
• Floors are randomly generated.
• Your inventory items and gitan are destroyed when you start a run, like most bonus dungeons. Make sure to store all items + bank all gitans before playing!
• You don't get a reward item for winning (like you do for most puzzles), but you do get to keep the items you acquired along the way (like most bonus dungeons).
• Some puzzles are instructive, helping you learn how to play the main game of Shiren, but like a bonus dungeon, Explosion Rocks isn't instructive per se.

The most apt way to think of Explosion Rocks is as a "minigame", much like minigames in other video game titles. It's the only minigame in Shiren 5, though, so it's in a category by itself. (The Lots Game in the basement of Hotel Nekomaneki could be thought of as a very trivial minigame. It's basically just a menu item though, not a dedicated location.)

Differences From Classic Minesweeper

As stated above, Explosion Rocks is basically a Shiren take on Minesweeper. If you're good at Minesweeper, you can probably beat all difficulty levels of Explosion Rocks without knowing much about Shiren at all. If you're not good at Minesweeper, you'll need to learn how to play and master Minesweeper, and you might be able to learn and practice faster with other implementations of Minesweeper elsewhere on other platforms or online. (E.g. the Windows and online versions of Minesweeper let you play much faster than the Shiren version, and thus gain experience and learn how to master it faster.)

Explosion Rocks floors are usually much smaller than bonus dungeons floor. Each floor is rectangular, surrounded by a 1-square-wide water moat border, and what appears to be the usual 1-square-wide unbreakable wall border outside of the water moat. (There is no way to cross the water to try testing the exterior boundary wall.) As in Minesweeper, the higher the difficulty, the larger the floor and also the higher the density of landmine traps. Floors are randomly generated, with a much higher frequency of landmine traps than in bonus dungeons, no other types of traps, and drawing from a very limited set of items and monsters. For some reason, the Squid Sushi Scroll is very common in Explosion Rocks. In fact, scrolls on floors 1-4 are almost always Squid Suchi Scrolls. You can throw a Squid Sushi Scroll at a Squid family monster to turn it into food (an Onigiri), but Squids don't appear in Explosion Rocks, so the only thing they seem to be good for is just carting them out of the dungeon and selling them or possibly using them in dungeons that let you take items in. Well, if you ever wanted to collect a large number of Squid Sushi Scrolls for whatever reason, Explosion Rocks is the place for you. Floors 1-4 all seem to be generated using the same algorithm, placing exactly 6 items (on Expert mode) randomly about the floor, drawn from a variety of grasses, the Squid Sushi Scroll, some other scrolls (very rarely), and gitan bags. Floor 5, the final floor, has 15 items (on Expert mode), drawn from a wider set of possible items, and the items tend to be much more valuable as well.

Most squares in the playfield start covered with breakable walls. All empty squares and landmine traps begin covered in breakable walls, and any monsters that exist are also on top of landmine traps and thus also covered by breakable walls. These monsters are unable to move or do anything until you break the walls covering them. (Open question: did they start in a paralyzed state, or is this just the effect of being covered by a breakable wall? It's unclear.) But once a monster is revealed, it moves and attacks as normal after your next turn. The only squares that aren't covered with breakable walls to begin with are Shiren's starting square (one step NE of the SW corner), the exit stairs (one step SW of the NE corner), and the few squares with pre-placed items on them scattered about the playfield. (You can never find items under breakable walls in Explosion Rocks, just empty space, a landmine trap, or a landmine trap with a monster on top.)

As in classic Minesweeper, when you break a wall that has open space underneath, it either shows you a number from 1-7 which is the number of landmine traps around that location, or, it shows blank floor meaning there are 0 landmine traps around that location. If 0, all adjacent breakable walls are also removed as a group, and this is repeated recursively if any new "0" locations are revealed. (In this case, they all disappear as a group all at once.) Why only numbers 1-7 instead of 0-9? In most modern Minesweeper variants, showing the 0s is considered needlessly cluttering, and if you talk to the old lady in the Dungeon Center who runs the Explosion Rocks game she says the maximum value is 7, which presumably means the game does not allow squares with 8 or 9 mines around them to be generated. (Numbers are not shown for squares that have mines on them, so you could never see a 9 even if the game generated a level that way and even if you had a way to safely uncover it. Likewise, if the game did generate a square with 8 mines around it, you could never reach it.) Spaces that contain items and thus start uncovered by breakable walls also show a digit (or no digit for 0), though it can be hard to read until you pick up the item. Shiren always starts on a "0" location, so it is safe to open all the walls immediately around Shiren's starting position. No digit is shown for the stairs location, or perhaps the stairs just fully cover the digit on the floor underneath, but the stairs are not always a "0" location.

(Note that, across Shiren 5, breakable walls are apparently generated in groups. If you hit a breakable wall that is part of a group, the entire group falls all at once. So, in a bonus dungeon, you can reveal an entire hallway this way -- but not all connected hallways or all connected rooms that are also covered with breakable walls, as these are apparently different breakable wall groups. In Explosion Rocks, most breakable walls are apparently in groups of just 1 breakable wall, but a set of connected 0-mine locations are in a group together so they all fall together as well.)

If you open a breakable wall with a monster on top, (a) there is a landmine trap there as well but it doesn't go off and (b) the monster is set loose to begin moving after your next turn, so you have one turn to react to the appearance of the monster. If you open a breakable wall with a landmine trap on it and no monster, the landmine trap detonates, bringing you down to just 1 HP or killing you if you were already at 1 HP. A landmine trap detonation does not break any of the adjacent breakable walls, but it does kill any adjacent, revealed monsters.

As in most Minesweeper implementations, you can tag spaces as known landmine traps, in this case by using the cursor joystick to highlight the wall in question and the left shoulder button to toggle it as a known mine. There is no counter of remaining untagged landmine traps however. Most Minesweeper implementations allow you to open locations anywhere on the playfield, but in this one, you usually need to move Shiren horizontally or vertically adjacent to the location you want to open and punch it. Punching diagonally doesn't break the wall, nor can you move diagonally if there is a wall space in either of the other 2 spaces that share the same corner, which makes it slightly more difficult than other Minesweeper games where the player has a presence on the board and where diagonal moves are allowed. (You can move diagonally if the 2 spaces that share the same corner have no wall, even if those spaces have landmines on them.)

You start each game of Explosion Rocks with a small, fixed set of items every time: one Large Onigiri and two 4-2-8 explosive pots. (It's possible the Large Onigiri comes from unlocking something in one of the Starting Villages that gives you a Large Onigiri at the start of every dungeon, rather than being something specific to Explosion Rocks. The two explosive pots on the other hand are definitely unique to Explosion Rocks.) The explosive pots can be thrown at walls from a distance. As usual, you can throw them a maximum of 10 spaces, and they will stop before 10 spaces if the next space is not open. Then the pot explodes, destroying itself + all breakable walls + all items + all monsters in the 3x3 area around where the pot stopped moving. (Open question: can a monster ever survive such an explosion? It seems that all monsters, no matter how strong, always die immediately when next to an explosion. This is definitely true in Explosion Rocks -- none of the monsters are particularly strong anyway.) Thus you can use the pots from a distance to open more squares without taking damage from landmine traps, monsters, or the explosive pot itself.

As in a storage location, Shiren doesn't heal by moving or passing turns in Explosion Rocks. Also, Shiren starts with a full belly, but it is possible to die of starvation if you take too many turns playing the minigame.

Final Reward

You do not get a reward item for winning Explosion Rocks, but you do get to keep items you found and didn't use in your minigame. See Farming Opportunities below for more details. You do get a PSVita trophy if you beat all difficulty levels at least once, and the game does keep track of how many times you've won in the Adventure Footprint (combined across all difficulty levels).