Famicom PPU Chess

This game is inspired by limitation of Famicom PPU.

Setup

This diagram shows start positions, where uppercase are sprite pieces and lowercase are tile pieces. Unfortunately, it doesn't tell you which color they are, but you can figure out all that are join in one part, is of one color.

##RNBQkbnr##
##PPCPpcpp##
rpv.P..p.VPR
np........PN
bcp......PCB
kp...##...PQ
QP...##...pk
BCP......pcb
NP........pn
RPV.p..P.vpr
##ppcpPCPP##
##rnbkQBNR##

This diagram show you the "attribute areas".

##..**..**##
##..**..**##
..**..**..**
..**..**..**
**..**..**..
**..*##.**..
..**.##*..**
..**..**..**
**..**..**..
**..**..**..
##**..**..##
##**..**..##

Pieces

Pieces can be sprites pieces or tiles pieces. Their difference is mentioned below in the rules; it doesn't affect their normal method of movement, however.

There is a King of Tiles of each color already present on the board. However, each player also has a King of Sprites of each color available for that player to drop on that player's turn.

It is not possible for a King of Sprites to castle.

The "C" designates Cannon. It is same as the Chinese Cannon; however, optionally you can change piece it jumps over (the "screen") from Sprites to Tiles or vice versa, except kings (but see further restriction below). Also, it is not allowed for a cannon to use a forward move to jump over a pawn you own in order to capture a pawn belonging to the player across from you.

The "V" designates Virgin (the V in southwest corner belongs to the West player, and so forth). It moves as FIDE queen, but cannot capture anything, and cannot leave their own 4x4 corner of the board (four of which are holes). It prevent any piece starting its move adjacent to it from making capturing moves. However, it can still be captured, except by knights. Also, it can be captured by kings despite being adjacent to it.

Pawns cannot capture other pawns that hasn't yet been moved.

En passan is allowed before the player who moved the pawn two spaces gets another turn (regardless if they pass or not), and regardless which direction the pawn doing capturing is moving in.

Pawns promote into a queen, knight, rook, bishop, or cannon. Pawn of Sprites must promote into pieces of Sprites, and Pawn of Tiles must promote into pieces of Tiles.

The "#" designates holes in the board. These holes cannot be crossed except by knights, and no pieces may stand there for any reason.

Rules

Game is played in teams, South+East vs North+West. Turn order is East, North, West, South.

No check/mate, and castling is allowed even into/through/out of check.

It is allowed to capture pieces of different colors than yourself, even if it is on the same team.

Player with no legal moves passes. If all players pass, the game is ended in a draw.

As a turn, a player may drop his King of Sprites on any vacant space on the board. This can be done once per game for each player.

Player with no king on board cannot move any pieces, but is still allowed to drop a King of Sprites if they haven't yet done so (and must do so if it is their only legal move).

Any team with no king on board is losing the game immediately.

No move is allowed unless you are capturing the last remaining king of opposing team, or the "Famicom PPU conditions" are met at the end of that move:

• Any 2x2 "attribute area" is not allowed to contain more than one color of "tiles" pieces.
• No horizontal row (regardless of orientation of the pieces moving) is allowed to contain more than eight "sprites" pieces.