Block Chain

Your goal: match five of the same symbol in a horizontal line. Move with WASD, and rotate left or right with Q or E.

This is a game that runs on a PC, but not under Windows or Linux. It is a boot-sector game. The computer can directly boot the game with no OS at all!  There are plenty of ways you can run the game:

• DOSBox: "BOOT blockchain.bin". From the command-line: dosbox -c 'boot blockchain.bin'
• QEMU: From the command-line: qemu-system-i386 -drive format=raw,file=blockchain.bin
• 86Box: Attach the "blockchain.img" file that has been padded to the length of a full 160K floppy disk. Configure a machine with 8088 or better; I found good results using the original IBM PC with video over an [ISA] CGA adaptor.
• If you're feeling particularly brave, it is possible to flash a bootable USB and try on a real PC. It works on my laptop, but I cannot guarantee safety or compatibility with your system.

However you go about loading the game, you are presented with a grid of card suits. You want to match five or more of the same symbol in a single horizontal line. This clears them out, gives you points, and lets new pieces fall from above. Move with WASD, or rotate the 3x3 cell surrounding your cursor with Q (left) or E (right). Be careful! You only get five rotations before you lose. These are refreshed each time you clear some pieces. When you have zero available rotations, this is the end of the game. Go for a high score! Press a rotate button to reset.

The code portion is well below even 440 bytes, leaving room for a partition table — you can still put files on a drive that boots this game!