LJ65
From Nesdev wiki
LJ65 is an action puzzle game for NES developed by Damian Yerrick, similar to AINT, Quadrapassel, Tetris, Lockjaw, and Bedter.
- Board: NROM
- Size: 16 KiB PRG, 4 KiB CHR
- Region: Separate ROMs for NTSC and PAL
- Language: English
- License: GNU General Public License
- Latest version: 0.41 (June 2009)
The game is played with puzzle pieces made of four square blocks. The blocks form seven distinct shapes, each with its own color. As the pieces descend into a well 10 blocks wide, the player can move and turn them. A half second after a piece lands, it locks into place, and the next piece comes out. Once an entire row of the well becomes filled with blocks, those blocks disappear (a "line clear"), and the blocks above it will move down by a row. Line clears with successive pieces are worth increasing points until a piece lands without clearing a line. The goal is to keep the well from filling up by clearing lines even as the pieces descend faster and faster. In the 2-player competitive mode, a player can add "garbage" lines in the other player's well by clearing more than one line with a single piece.
LJ65 shows that the NES can do things expected by avid players of modern falling block games:
- Fast sideways motion to get pieces to the sides of the well reliably
- Shadow, or an outline of where the falling piece will land
- Separate colors for each piece, shown on both the falling piece and (through dithering) the blocks in the well
- Two rotation systems, based on the center or the bottom of the falling piece
- Initial rotation, or being able to rotate a piece before it comes out
- Wall kick, or a slight nudge when a piece rotates into a wall
- Demonstration with text explaining the game rules
LJ65 is notable for exposing a bug in the PPU's OAM refresh when the program turns off rendering early while a sprite is still in range, causing a semi-random pair of sprites to flicker. Later versions of LJ65 work around this.
