Mario's Picross was a very nice attempt at making a Mario game based on Picross puzzles (Or nonograms, as they're sometimes called), but there were a few shortcomings - the biggest of which was that most puzzles just weren't really hard. With a maximum size of 15x15, the game's "toughest" puzzles just didn't actually provide much challenge!
Picross 2's main goal seems to be to fix these things and add as many new features as it possibly can. The game starts off with an "Easy Picross" mode, but unlike the first game, this doesn't include 64 different puzzles - there's only 10, and all of them are the same size as the first game's toughest puzzles - 15x15. This means there's not much time to practice before you get to the meat of the game, but we'd recommend you play the first game before touching this one anyway.
After Easy Picross, you're likely to be in for a shock - almost every single puzzle afterward is 30x30 tiles big instead! You're not shown all 900 tiles at the same time though; each of these giant puzzles is actually really divided into 4 smaller 15x15-sized puzzles. You'll always start with the top-left section, but after clearing it, you're free to select any of the three remaining ones, and so forth, until all four sections have been solved to create one extra big solution.
At the start of the game, each section has its own 30-minute time limit, so as you can imagine, each full 30x30 puzzle can take quite a while to solve. But as you reach later worlds, this time limit will decrease - for example, starting from world 4, you'll only have 90 minutes to finish all four sections. To help slightly, there is a new option on the pause menu; in exchange for 5 minutes of the time, you can get another hint, just like at the start of the puzzle. Hints here work exactly the same as in the first Picross game - two "roulette" wheels will select one row and one column to chisel out completely.
Another interesting new addition is that there's actually a "story mode" of sorts. In this game, you actually get to move around as Mario, decked out in his explorer's gear. Unlike the first title, where you were just given a giant batch of puzzles which you could do in any order, here, the game is divided into 9 "worlds". To access the next world, you must solve all puzzles in the previous one. Each world features an actual map you can walk around with Mario, with stone slabs strewn around. Standing in front of one of them lets you attempt its puzzle. The solution will appear on the stone slab when you finish, thus decorating the place a little. Each of the maps is fairly nicely detailed, giving the game a bit more charm.
Each world actually also has a secret 10th puzzle, but unlocking them might be more trouble than they're worth. To unlock the final puzzle, you must finish all other 9 in that world without using hints (this includes declining the free hint at the start of each puzzle), without running out of time, and without giving up. As you can imagine, this could take quite a lot of retries if you're not extremely good, and the "reward" isn't really worth bothering with - each of the secret puzzles is 30x30 in size as well, and their solutions aren't really interesting or different compared to the standard 9. Only perfectionists should really bother trying to get these. Obviously, it is not required to unlock and complete these to reach the next world.
You might be wondering why Wario is on the game's boxart. Simple - after clearing Mario's first world, Wario will suddenly make an appearance and from that moment on, you can not just play Mario's Picross, but Wario's Picross as well, which includes another 9 worlds of different puzzles! This plays similarly to the Time Trial mode in the original Mario's Picross, which was the final mode you could unlock - you're never told when you've made mistakes, meaning that you won't know you've made an error or not until you're stuck or you finish.
Don't worry though, because this mode has a new option on the pause menu as well, replacing Mario's extra hint option. Wario can activate a "test" mode, in which you can continue puzzling without actually chiselling out anything. If you then manage to get stuck, you can select to undo everything you just did. If you actually did the right thing, of course, you can also choose to save the changes. This makes Wario's Picross a lot less frustrating. Wario's mode can also be played without a time limit, but be warned, because you're required to keep it turned on if you want to unlock Wario's secret 10th puzzles.
After every 3 worlds, for both Mario and Wario, the game has another surprise in store for you - you'll play a number of "Quick Picross" puzzles. Each of these is only 8x8 in size, but you have to solve a number of them in a row within a certain time limit before you're allowed to continue! The solutions to all of these puzzles are Japanese hiragana and katakana characters, so for most western players, it won't be very easy to see what the image is supposed to be before it is completely finished.
But that's still not the final surprise. After beating all 9 worlds and 3 rounds of Quick Picross, Mario or Wario is faced with one final puzzle, which is, to this day, still the greatest challenge in any Picross game - they will have to solve an absolutely titanic final puzzle which is 60x60 in size, meaning there's 3600 blocks! Like every other big puzzle, it's divided into 15x15 sections, meaning that there's not 4 sections, but a whopping 16!
Both of these (Mario's and Wario's) will take you multiple hours to beat, but when you do actually manage to clear one or both of them you really deserve to give yourself a pat on the back. It's at this time that another of the game's new features comes in real use - you can save your progress at any time and turn the game off. The next time, you can then continue at the exact same spot in the puzzle where you left off at!
Although the basic look of the puzzles is exactly the same as in Mario's Picross, Picross 2's graphics are ever so slightly more impressive because of Mario and Wario's 18 different overworld maps - all of them are quite detailed and fun to walk around. Sadly, even though the game does a lot of good things, one area has taken a huge hit. There's five different background songs to choose from during gameplay, just like in the first game, but none of them are very good at all - each of them will loop before you know it, and the compositions just aren't that interesting. It's a shame, because it means most of the time you'll be playing with boring, short tunes which will quickly begin to annoy. Therefore, for this game, it might be best to grab your iPod or crank up that stereo!
Nintendo's main objective with Picross 2 seemed to be to up the challenge and include new, helpful features. They've succeeded in both of these - aside from the Easy and Quick Picross puzzles, all of the puzzles included in Picross 2 are bigger and tougher than those found in Mario's Picross. Despite the fact that these puzzles are so big, they've still managed to get an astounding number of them in the game - Picross 2 features near 800 puzzles, which is an unbelievable step up from the first game's mere 250, and a ridiculous feat for a Game Boy game. The music might be a bit of a miss, but that's nothing that a personal MP3 player can't fix.
All in all, Picross 2 offers an enormous batch of extra puzzles for those who thought the first game didn't have enough. You might need to have some patience, because the puzzles in this one can take a while due to actually being divided into parts, but you're certain to get months - if not years - of gameplay out of this title. Be warned though, because it was only released in Japan, and it's somewhat rare; if you really want to get it, you'll have to have some money ready and be prepared to do a bit of searching online.