Prez


Engine: 6502

Prez is the second NES (Nintendo Entertainment System) game that I’ve developed, which was for the MiniLD #71 “Retro Challenge”.  You play as Prez and must collect the flags as they fall from the sky.  My first NES game was a very simple space shooter called Space Dude, which I created back in April 2014.  I tried a few new things for this game, such as using multiple palettes and using “random” values to position the flags.

Runs well with FCEUX 2.2.2. I haven’t tried other emulators.

Prez gameplay

Tools used:
NESASM3 – 6502 assembler
YY-CHR – tile creator
Gimp – converting white house image to four color palette

Things I would like to add:
Title screen
Music and sound effects

Prez collecting flags

Latest updates:
– Added a simple two frame animation walking loop
– Added speed variable (just one or zero) which tracks if the player is standing or walking. If standing, the animation loop isn’t played.
– Fixed the background vertical scroll issue (stored #$00 #$00 in $2005, which turns off scrolling)
– Moved the letters “FLAGS” to the background layer, which eliminated the tearing problem with too many sprites on the same horizontal row. I had to keep the score on the sprite layer, because I don’t know how to write over tiles in the background layer (or if it’s even possible)
– Made a seamless background of hedges that I put on both sides of the White House
– Due to the vertical scroll fix, I pushed the remaining tiles down one row. I was surprised that this made the ground in front of the White House look much better, since it moved the ground to the attribute block with the green grass palette.
– When a flag falls below a certain Y coordinate (defined with a constant), it resets to a “random” position at the top of the screen. Previously, the flag would just loop back to the top of the screen after the Y position value rolled back over from #$FF to #$00.

Download the latest version of the NES ROM at NESDev.

View the Prez development video archive.