The promoters show screenshots with code links you can run in the respective emulators:
http://gkanold.wix.com/homeputerium#!games-list-2016/c1jdtMy entry was
9LineBlitz for the Atari 2600 written in
Virtual World Tiny BASIC, here's the 9 lines of code to discuss; placed pretty well, maybe could have placed higher if I used that extra line
Was fun to compete like bitd!
0 data city 1,4,2,5,3,2,3,1,4,1,1,1,5,2,2,3,1,4,1,4,3,1,4,4,1,1,2,2,3,1,3,4,5,4,4,3,4,5,1,2,4,1,5,2,2,3,1,3,1,1,4,1
1 if g=0 then for j=0 to 7:player1(j)=189:player0(j)=pl(j):next j:BYTErowoffset=120:COLUPF=$84:COLUP0=$b4 else goto 3
2 for j=20 to 71:k=j-20:k=city(k)+14:for i=k to 19:vwpixel(j,i,on):next i,j:player0y=88:player0x=94:COLUP1=$74:y=20
3 COLUBK=0:AUDV0=0:g=1:scrollvirtualworldtoggle=1:BITIndex=BITIndex+1:data pl 0,224,127,231,252,192,128,0:rem bitmap
4 if joy0fire=1 and y>=20 then AUDF0=6:AUDC0=8:AUDV0=15:x=BITIndex+11:y=11:i=88-player0y:i=i/10:y=y+i
5 if y<21 then vwpixel(x,y,bindplayer1):j=y-10:y=y+1:COLUP1=M(j):data M $64,$54,$b4,$a4,$32,$44,$24,$c4,$94,$f4,$54
6 if y<=19 and vwpixel(x,y,poll)>0 then vwpixel(x,y,flip):player1x=0:player1y=0:AUDC0=y:y=20:AUDF0=4:AUDV0=15
7 if BITIndex>71 then BITIndex=0:player0y=player0y-2:rem player flies lower each pass over the smoothly scrolling city
8 if CXP0FB>126 then CXCLR=0:g=0:for i=0 to 255:AUDF0=i:AUDV0=i:COLUBK=$34:next i:rem check collision, restart game
Here's what's going on in the BASIC:
Lines 1 and 2 are setup routines and use a couple of for next loops to draw a city on the large virtual world and to load a player sprite with a bitmap, reading the data from named arrays.
The rest of the program uses the blitter commands and objects surfaced to the BASIC to smoothly scroll the virtual world at 30 frames per second of full screen animation while floating the player sprite and tile mapping it's flashing disco missiles by binding them to the scrolling background at 30 FPS while they are falling at a slower speed with the Y axis unbound (but also 30 FPS) for a neat visual effect; these are all features of the soft blitter chip in the runtime (tile mapping, flipping and sliding the entire display around while all of the sprites and playfield graphics are also moving relative to themselves).