So, uh, how do you play this?
I just downloaded and gave it a try. How do you attack other players? And how do you defend from attacks?
I have a good start and then my screen starts filling up with grey blocks due to other players and I have no idea what to do. There's no guide anywhere in game.
By default, your targeting is random. Every set of lines you clear, sends "damage", or garbage lines, to another player. You can see who you're attacking by the green targeting hexagon on the field. You can see who's attacking you by the yellow lines coming from the field to the bottom of your screen.
You can choose whom to attack manually with the left stick, or pick a method of automatic targeting with the right. (or vice versa, if you choose the other control pattern in options)
R-stick up is "KOs", the autotarget will pick players closest to being knocked out.
R-stick left is "Random" the default setting.
R-stick right is "Badges", targeting players who have the most KO badges (and are thus the most threatening, the badges multiply damage).
R-stick down is "Counter", and will target every player who is targeting you.
A stack of blocks to the left of your play area indicates incoming damage. Colored blocks indicate imminent garbage lines, coloring from yellow to red. These count down placed blocks rather than time, so rushing is ill-advised. Red flashing blocks indicate the garbage lines will appear as soon as you place the next block. Any lines you clear while you have incoming damage, will clear incoming damage instead of damaging another player - thus the way to defend is to stay ready to clear lines once you see a mass of incoming damage.
Grey blocks in the damage indicator show a stack of damage from another player - two players can't simultaneously drop active damage on you, the greyed damage will only become active once the ongoing colored damage clears. It will activate all at once though, so be ready.
Generally the way to stay in the running later in the match is making sure you have the maximum four badges, as this maximizes your "damage" both for offense and defense - so it may be a good idea to use "badges" targeting at some point to collect your victims' badges. Using the "counter" targeting mode also multiplies your damage output, making it a good mode to use in the midgame, or any other time a lot of people are attacking you and you need the extra damage to defend yourself.