My first complete game in DBP, There were some aspects I struggled with such as bullet movement, bonus enemies etc so I posted it here for all to see.

You pilot a spaceship at the bottom of the screen moving left and right. You have to shoot enemies coming from the top of the screen Which get faster and faster as the levels go up. Your allowd to let 5 enemies get past you before you lose a life. Every so often a yellow bonus star will appear, shooting this nets you 500 points missing it does nothing but letting it hit you loses you 500 points.

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    Rem Project: Space Wave
Rem Created: 04/03/2004 17:40:53
` COPYRIGHT Oliver Fishwick 2004
` Created in 10 days
Rem ***** Main Source File *****

set display mode 800,600,32
hide mouse

backdrop off
cls rgb(10,10,10)
randomize timer()
plx#=350
ply#=540
bux#=350
buy#=540
enx#=(rnd(800))
eny#=-100
score#=0
target#=100
level#=1
enspeed#=1
lives=3
missed=5
enemies_shot=0
stry#=-10000
strx#=(rnd(600))
strspeed#=2
sync on




load image "player ship.bmp",1
sprite 1,plx#,ply#,1
spritewidth=(sprite width(1)/2)
spriteheight=(sprite height(1)/2)
offset sprite 1,spritewidth,spriteheight
hide sprite 1

load image "bullet.bmp",2
sprite 2,bux#,buy#,2
spritewidth=(sprite width(2)/2)
spriteheight=(sprite height(2)/2)
offset sprite 2,spritewidth,spriteheight
hide sprite 2

load image "enemy grunt.bmp",3
sprite 3,enx#,eny#,3
hide sprite 3

load image "explosion.bmp",4
sprite 4,enx#,eny#,4
hide sprite 4

load image "player explosion.bmp",5
sprite 5,plx#,ply#,5
spritewidth=(sprite width(5)/2)
spriteheight=(sprite height(5)/2)
offset sprite 5,spritewidth,spriteheight
hide sprite 5


load image "start screen.bmp",6,1
sprite 6,0,0,6
hide sprite 6

load image "bonus star.bmp",7
sprite 7,strx#,stry#,7

load image "bonus star shot.bmp",8
sprite 8,strx#,stry#,8
hide sprite 8

load image "bonus star miss.bmp",9
sprite 9,strx#,stry#,9
hide sprite 9

load image "logo.bmp",10,1
sprite 10,20,150,10

load music "background.mid",1
load sound "explosion.wav",1
load sound "next level.wav",2
load sound "points up.wav",3
load sound "points down.wav",4
load sound "chimp.wav",5




play sound 5
repeat
sync
x=x+1
until x=500
delete sprite 10
delete sound 5

show sprite 6
repeat
sync
until returnkey()=1
delete sprite 6








`%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

main_loop:
do
loop music 1
gosub player_movement
gosub bullet_movement
gosub enemy_movement
gosub collision_detection
gosub player_stats
sync
loop
`%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


`&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
player_movement:
if eny#>-30
  show sprite 1
  show sprite 3
  hide sprite 5
  sprite 1,plx#,ply#,1
  sprite 5,ply#,plx#,5

if leftkey()=1
  plx#=plx#-1.75
endif
if plx#<0 then plx#=0

if leftkey()=1 and buy#=540
  bux#=bux#-1.75
 else buy#=buy#-0
endif

if bux#<0 then bux#=0


if rightkey()=1 and buy#=540
  bux#=bux#+1.75
 else bux=bux+0
endif

if bux#>800 then bux#=800

if rightkey()=1
  plx#=plx#+1.75
endif

if plx#>800 then plx#=800

sprite 1,plx#,ply#,1
sprite 2,bux#,buy#,2
endif
return

`&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

bullet_movement:
if spacekey()=1
  show sprite 2
  bullet_move=1
endif

if bullet_move=1
  buy#=buy#-2
endif

if buy#<0
  bullet_move=2
endif

if bullet_move=2
  bux#=plx#
  buy#=ply#
  hide sprite 2
endif

return

`&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

enemy_movement:
  eny#=eny#+enspeed#
if eny#>600
  missed=missed-1
  eny#=0
  enx#=(rnd(600))
endif
  sprite 3,enx#,eny#,3

stry#=stry#+strspeed#
if stry#>600
strx#=(rnd(600))
stry#=-10000
endif
sprite 7,strx#,stry#,7

return

`&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

collision_detection:
if sprite hit(2,3) and buy#<540
  enemies_shot=enemies_shot+10
  play sound 1
  show sprite 4
  eny#=-30
  enx#=(rnd(600))
  bullet_move=2
  score#=score#+10
endif

if eny#>10
  hide sprite 4
  sprite 4,enx#,eny#,4
endif

if sprite hit(1,3)
  play sound 1
  lives=lives-1
  eny#=-100
  hide sprite 1
  show sprite 5
endif
  sprite 1,plx#,ply#,1
  sprite 5,plx#,ply#,5

if sprite hit (2,7) and buy#<540
  play sound 3
  enemies_shot=enemies_shot+500
  show sprite 8
  stry#=-10000
  strx#=(rnd(600))
  bullet_move=2
  score#=score#+500
endif

if stry#>-9000
  hide sprite 8
  sprite 8,strx#,stry#,8
endif

if sprite hit(1,7) and stry#>0
  play sound 4
  show sprite 9
  stry#=-10000
  strx#=(rnd(600))
  bullet_move=2
  score#=score#-500
  enemies_shot=enemies_shot-500
endif

if stry#>-9000
  hide sprite 9
  sprite 9,strx#,stry#,9
endif

return

`&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

player_stats:
set text size 18
set text to bold
text 10,10,"score "+str$(score#)
center text 370,10,"level "+str$(level#)
text 10,30,"miss"+str$(missed)
text 10,50,"lives "+str$(lives)

if target#=score#
  target#=target#*2
  level#=level#+1
  play sound 2
  enspeed#=enspeed#+0.25
endif

if enemies_shot=>1000
  lives=lives+1
  level#=level#+1
  enemies_shot=0
  enspeed#=enspeed#+0.25
endif

if lives=1
  center text 370,30,"NEAR DEATH"
endif

if missed=0
 lives=lives-1
 missed=5
endif

if lives=0
  hide all sprites
  stop music 1
  set text size 40
  center text 370,280,"GAME OVER"
  set text size 15
  center text 700,580,"copyright Oliver Fishwick 2004"
  center text 370,330,"Enter=Try Again"
  center text 370,350,"Esc=Exit"
  center text 370,380,"Programming&Graphics   Oliver Fishwick"
  center text 370,390,"Logo Design   Michael Eddie"
  center text 370,400,"Sound   PartnersInRhyme"
  center text 370,410,"Thanks to everyone on the DarkBASIC forums!!!"
 if returnkey()=1
  lives=3
  score#=0
  enemies_shot=0
  show sprite 3
  show sprite 7
  if escapekey()=1
  end
 endif
 endif
endif

return