Guided Project
Guided ProjectReach the shelter before a huge pigeon catches you. Under the absurd premise is a precise system of coordinates, collision checks, and two possible endings.
The finished game
Guide the Player from the lower-left corner to the striped Safe Zone while an oversized pigeon closes in. The arrow keys change x and y, Game State keeps the two endings from colliding, and R runs the same complete reset as the green flag.
Project system sketch
Letters A–F mark the positions, movement, pursuit, collision priority, Panic meter, and state changes.
What you need
This project runs in the browser-based Scratch editor, so there is nothing to install. An account is optional; available saving and sharing methods depend on the classroom setup.
Project downloads
Begin with the starter, inspect the finished game, or download the editable art and sounds.
Original art and sounds, named variables, known positions, and setup scripts. The game systems are yours to build.
Download Starter Project escape-from-the-giant-pigeon-starter.sb3The complete playable game shown in the code sections below.
Download Finished Game escape-from-the-giant-pigeon-finished.sb3Editable SVG costumes and backdrop, WAV effects, the project sketch, README, and licence notes.
Download Art and Sound Pack escape-from-the-giant-pigeon-assets.zipSystems you will build
Build them in order and test each one before moving on.
Build system
Gives every run the same starting state.
The flag broadcasts Reset Game. Its receiver sets READY, restores the variables and timer, waits for each actor to reset, then switches to PLAYING after a one-second pause.
ON green flag:
ask the whole project to reset
ON Reset Game:
set READY and restore every value
reset every actor
wait for a fair start
set PLAYINGwhen green flag clicked broadcast [Reset Game v] and wait
when green flag clicked
broadcast [Reset Game v] and waitwhen I receive [Reset Game v] set [Game State v] to [READY] stop all sounds set [Panic v] to (0) set [Survival Time v] to (0) set [Pigeon Speed v] to (2) reset timer broadcast [Reset Actors v] and wait wait (1) seconds set [Game State v] to [PLAYING] play sound [start v] until done
when I receive [Reset Game v]
set [Game State v] to [READY]
stop all sounds
set [Panic v] to (0)
set [Survival Time v] to (0)
set [Pigeon Speed v] to (2)
reset timer
broadcast [Reset Actors v] and wait
wait (1) seconds
set [Game State v] to [PLAYING]
play sound [start v] until donewhen I receive [Reset Actors v] set rotation style [left-right v] go to x: (-190) y: (-110) switch costume to [normal v] show say []
when I receive [Reset Actors v]
set rotation style [left-right v]
go to x: (-190) y: (-110)
switch costume to [normal v]
show
say []when I receive [Reset Actors v] go to x: (190) y: (-115) switch costume to [inactive v] show
when I receive [Reset Actors v]
go to x: (190) y: (-115)
switch costume to [inactive v]
showBuild system
Reads the arrow keys and changes x or y.
Movement runs only during PLAYING. Right and left change x; up and down change y. Because each key has its own check, holding two keys moves the Player diagonally.
WHILE the game is playing:
read the arrow keys
change x for left or right
change y for up or downwhen green flag clicked
forever
if <(Game State) = [PLAYING]> then
if <key [right arrow v] pressed?> then
change x by (5)
end
if <key [left arrow v] pressed?> then
change x by (-5)
end
if <key [up arrow v] pressed?> then
change y by (5)
end
if <key [down arrow v] pressed?> then
change y by (-5)
end
end
end
when green flag clicked
forever
if <(Game State) = [PLAYING]> then
if <key [right arrow v] pressed?> then
change x by (5)
end
if <key [left arrow v] pressed?> then
change x by (-5)
end
if <key [up arrow v] pressed?> then
change y by (5)
end
if <key [down arrow v] pressed?> then
change y by (-5)
end
end
endBuild system
Keeps the whole Player visible inside the stage.
Four comparisons watch the current x and y positions. When the Player passes a limit, the script puts the matching coordinate back on the edge.
FOREVER during PLAYING:
if x passes either side, put x on the edge
if y passes top or bottom, put y on the edgewhen green flag clicked
forever
if <(Game State) = [PLAYING]> then
if <(x position) > (218)> then
set x to (218)
end
if <(x position) < (-218)> then
set x to (-218)
end
if <(y position) > (158)> then
set y to (158)
end
if <(y position) < (-158)> then
set y to (-158)
end
end
end
when green flag clicked
forever
if <(Game State) = [PLAYING]> then
if <(x position) > (218)> then
set x to (218)
end
if <(x position) < (-218)> then
set x to (-218)
end
if <(y position) > (158)> then
set y to (158)
end
if <(y position) < (-158)> then
set y to (-158)
end
end
endBuild system
Returns the pigeon to its known starting position and appearance.
Reset Actors restores the pigeon's position, direction, costume, and visibility. The Stage stays in READY for one second, so the pigeon cannot begin chasing early.
ON Reset Actors:
stop any old chase appearance
move far from the Player
face left, show wings up, and showwhen I receive [Reset Actors v] set rotation style [all around v] go to x: (155) y: (100) point in direction (-90) switch costume to [wings up v] show
when I receive [Reset Actors v]
set rotation style [all around v]
go to x: (155) y: (100)
point in direction (-90)
switch costume to [wings up v]
showBuild system
Points towards the Player and moves by Pigeon Speed.
The loop aims again after every move because the Player's position keeps changing. A short wait controls the chase speed and leaves enough time to see the wing costumes alternate.
WHILE the game is PLAYING:
point toward the Player's current position
move by Pigeon Speed
flap once and pause brieflywhen green flag clicked
forever
if <(Game State) = [PLAYING]> then
point towards [Player v]
move (Pigeon Speed) steps
next costume
wait (0.08) seconds
end
end
when green flag clicked
forever
if <(Game State) = [PLAYING]> then
point towards [Player v]
move (Pigeon Speed) steps
next costume
wait (0.08) seconds
end
endBuild system
Sets CAUGHT once when the Player touches the pigeon.
The outer Game State check prevents a repeated ending. The script sets CAUGHT before broadcasting, so every other PLAYING system stops at its next check.
WHILE PLAYING:
if touching the Giant Pigeon:
set CAUGHT first
announce Caughtwhen green flag clicked
forever
if <(Game State) = [PLAYING]> then
if <touching [Giant Pigeon v]?> then
set [Game State v] to [CAUGHT]
broadcast [Caught v]
end
end
end
when green flag clicked
forever
if <(Game State) = [PLAYING]> then
if <touching [Giant Pigeon v]?> then
set [Game State v] to [CAUGHT]
broadcast [Caught v]
end
end
endBuild system
Sets SAFE only when the Player reaches the shelter without touching the pigeon.
The outer not-touching-pigeon check gives CAUGHT priority when both contacts appear to happen together. Only after that check does the script test the Safe Zone.
WHILE PLAYING:
if NOT touching the pigeon:
if touching the Safe Zone:
set SAFE first
announce Reached Safetywhen green flag clicked
forever
if <(Game State) = [PLAYING]> then
if <not <touching [Giant Pigeon v]?>> then
if <touching [Safe Zone v]?> then
set [Game State v] to [SAFE]
broadcast [Reached Safety v]
end
end
end
end
when green flag clicked
forever
if <(Game State) = [PLAYING]> then
if <not <touching [Giant Pigeon v]?>> then
if <touching [Safe Zone v]?> then
set [Game State v] to [SAFE]
broadcast [Reached Safety v]
end
end
end
endBuild system
Calculates Panic from distance and records survival time.
Panic rises as the pigeon gets closer. Two checks keep it between 0 and 100. A separate Stage script records the timer to the nearest tenth while the game is PLAYING.
WHILE PLAYING:
Panic = 100 - rounded(distance / 4)
clamp Panic between 0 and 100
Survival Time = timer rounded to tenthswhen green flag clicked
forever
if <(Game State) = [PLAYING]> then
set [Panic v] to ((100) - (round ((distance to [Giant Pigeon v]) / (4))))
if <(Panic) < (0)> then
set [Panic v] to (0)
end
if <(Panic) > (100)> then
set [Panic v] to (100)
end
end
end
when green flag clicked
forever
if <(Game State) = [PLAYING]> then
set [Panic v] to ((100) - (round ((distance to [Giant Pigeon v]) / (4))))
if <(Panic) < (0)> then
set [Panic v] to (0)
end
if <(Panic) > (100)> then
set [Panic v] to (100)
end
end
endwhen green flag clicked
forever
if <(Game State) = [PLAYING]> then
set [Survival Time v] to ((round ((timer) * (10))) / (10))
end
end
when green flag clicked
forever
if <(Game State) = [PLAYING]> then
set [Survival Time v] to ((round ((timer) * (10))) / (10))
end
endBuild system
Shows the result with a costume, sound, message, and Safe Zone change.
The detector commits the Game State before the ending receivers change the presentation. Movement and pursuit stop because their scripts only run during PLAYING.
ON Caught:
show caught costume and sound
explain how to restart
ON Reached Safety:
activate the shelter and play its sound
explain how to restartwhen I receive [Caught v] switch costume to [caught v] play sound [caught v] until done say [CAUGHT! Press R to restart.]
when I receive [Caught v]
switch costume to [caught v]
play sound [caught v] until done
say [CAUGHT! Press R to restart.]when I receive [Reached Safety v] say [SAFE! Press R to restart.]
when I receive [Reached Safety v]
say [SAFE! Press R to restart.]when I receive [Reached Safety v] switch costume to [active v] play sound [safe v] until done
when I receive [Reached Safety v]
switch costume to [active v]
play sound [safe v] until doneBuild system
Sends the R key and green flag through the same reset.
There is one Reset Game receiver, so a repair applies to both ways of restarting. R works after a win, after a loss, and during play.
ON R key:
ask for Reset Game and wait
THEN test green flag, win-restart, caught-restart, edges, overlap, and variableswhen [r v] key pressed broadcast [Reset Game v] and wait
when [r v] key pressed
broadcast [Reset Game v] and waitTest checklist
One easy win proves very little.
Check all four boundary comparisons. The x rules must set x, and the y rules must set y.
Check both reset positions, then confirm that pursuit runs only while Game State equals PLAYING.
Keep the Safe Zone check inside the not-touching-pigeon condition. Set Game State before broadcasting the ending.
Check every Reset Actors receiver. It must restore costume, visibility, speech, and position.
The formula subtracts scaled distance from 100. Two later checks keep the result between 0 and 100.
Challenges
Change Pigeon Speed to 3 and test three routes. Adjust one starting coordinate until a careful player can still win.
Add sandwich crumbs that reduce Panic without changing Game State. Explain how each crumb can trigger only once.
Create a second original backdrop with a new Safe Zone. Reset the stage number, actor positions, and collision rules without copying the whole game.
What to demonstrate
Explain one coordinate change, one state transition, one edge-case test, and one improvement you made.
Change the look
Every costume and sound can be replaced. Keep the sprite names and costume centres aligned with the code, then make the chase look and sound like your own game.
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