Picross has always been one of the weirder puzzle games at which Mario has tried his hand. It seems very boring to slowly create a picture using nothing but numbers, but once you get the hang of it the time simply flies by and you'll find yourself playing for hours on end.
Mario's Picross was the first game in which Mario attempted to solve these strange puzzles, and the only pre-DS Picross game to be released outside Japan originally. As such, it's also the only pre-DS Picross game to feature an English tutorial.
Picross is played on a grid, comprised of numerous small blocks. The grid increases in size as you get further in the game — early puzzles can be as small as 5x5, but the hardest puzzles will be 15x15. This is relatively small when compared to later Picross games — for example, in Mario's Super Picross, some puzzles are 20x25 in size.
Above and to the left of these blocks are a whole bunch of numbers. With your trusty hammer and chisel, you must chip away blocks on the grid corresponding to those numbers, eventually resulting in the creation of a pixellated picture. Let's assume the grid is 5x5 — if there is a "5" listed above a column, that means all 5 blocks in that column must be chiselled.
If there are two numbers listed above a column, that means there are two sequences of blocks in that column that must be chiseled. For example, if "2 2" is listed, there are two sequences, which are both 2 blocks in size — it also means that there must be at least one space between the two pairs, because otherwise, of course, they're not separate. Generally, it's best just to leave a row/column alone if you can't figure out the size of a gap and just continue on elsewhere; you'll figure it out sooner or later. In a 5x5-sized puzzle, though, there's exactly enough space for 2 blocks, 1 space, and 2 more blocks, so in that case it would be easy to figure out.
Thankfully, your chisel has a secondary function — if you believe that a block must not be filled in, you can scratch an "X" into it, so that you can easily tell that it should not be touched during the rest of the puzzle. This is extremely handy during bigger puzzles, so you should use it as much as possible.
The most important gameplay element is time, as you only have 30 minutes to complete every puzzle. Don't think it's that easy though — if you happen to chisel a wrong block, you'll lose two minutes of your time. If you make a second mistake, you'll lose four, and a third, fourth or fifth mistake will cost you eight minutes. Therefore, you should make as few random guesses as possible. If you can't even begin to figure out where to start, you can get a free hint at the outset of every puzzle. This will start a sort of roulette that you can stop at any time, and once it stops the row and column which are highlighted will be filled in completely.
The game starts you off with only two modes. "Easy Picross" features rather basic puzzles with many easy to figure out chisel spots, making it perfect for beginners. "Mario's Picross" is for more experienced players and has puzzles that are a bit more difficult to figure out, because there's generally multiple groups of blocks you must chisel in every row and column.
The Mario's Picross mode is divided into two groups of puzzles — the Kinoko (Mushroom) Course and the Star Course. You can only play the Star Course puzzles after beating all Kinoko Course puzzles, but there's not really any change in difficulty between the two. Each puzzle group - Easy, Kinoko and Star — has 64 puzzles, making for a total of 192 to solve.
When you've solved every single one of these, you'll unlock one final mode: Time Trial. This mode has another 64 puzzles, of which one is randomly selected every time you play (there is no list to pick from for this mode), but things play a little differently here: you can't get a hint, and you will be never be told when you make a mistake. On the positive side, this means you can't lose time due to mistakes, but on the negative side, you could waste a ton of time building off of a single wrong block that you’ve chiselled. This mode was expanded into "Wario's Picross" for other Mario's Picross games, with just as many puzzles as the Mario mode. In this title, however, it's limited to just these 64 puzzles.
Graphics and music-wise, Mario's Picross does a very nice job. The graphics are obviously not too special when compared to other games, but they're pleasant to look at and very appropriate for the game. During gameplay, you have a selection of five songs which you can change between at any time you want. They range from slow to upbeat, meaning there's something for both the slow, careful players and the fast, determined ones. Each of them is quite catchy as well, so it's no surprise some of them made a return in Mario's Super Picross. Although this title looks and plays the same way that it did on the original Game Boy, the usual 3DS Virtual Console features are present. This includes the suspended state save as well as the ability to create a restore point; both are useful if you need to take a break mid-puzzle.
With 192 "regular" puzzles and an additional 64 Time Trial puzzles, the value of Mario's Picross is impressive, containing over 250 puzzles that can easily be taken with you anywhere you go. They're not very hard compared to some of the brainteasers in the later games, which also have various extra features, but it's still a great, addictive piece of software, and a nice start for Picross beginners or those who just want some more puzzles to crack.