Computer Lab Project

The Suspiciously Emotional Space Pet

Keep an alien pet fed, rested, and reasonably trusting. It remains suspicious of the snack button.

Program: Scratch & Game Design
Project type: Computer Lab Project
Difficulty: Builder
Estimated time: 60-90 minutes

Project brief

What students build

At least two changing needs
Actions that affect those needs
Visible mood or state
Time-based change
A recovery path
A reset and demonstration state

What students learn

Variables as memory
Initialization
Connected state changes
Threshold decisions
Balancing systems
Explaining emergent behaviour

What students need

Browser
Scratch editor
Keyboard or mouse
Student-created pet design

Students choose the pet's needs, the scale for each value, and the rules connecting them. Different models are welcome if their behaviour can be explained.

Computer Lab brief

Choose the pet's needs and the rules connecting them. The finished version must show how its current values produce its visible mood.

Required systems

What must exist.

At least two changing needs
Actions that affect those needs
Visible mood or state
Time-based change
A recovery path
A reset and demonstration state

Suggested build order

One useful route through the problem.

Choose the needs Define two or three values the pet must remember.
Create care actions Connect buttons or keys to feeding, resting, or playing.
Let time matter Change at least one need at a controlled interval.
Show the state Use expressions, messages, or animation to show when a value crosses a threshold.
Test difficult combinations Try low energy, high hunger, and competing care actions.

Checkpoints

1Each variable has a clear name and starting value.
2Each action changes the intended values once.
3The change is slow enough to observe and test.
4Someone watching can tell why the pet looks different.
5The pet always has a recoverable state.

Challenge cards

Choose one, combine compatible cards, or propose an equivalent challenge.

CHALLENGE 1

Add a trust variable.

CHALLENGE 2

Make actions have trade-offs.

CHALLENGE 3

Create a day/night state.

CHALLENGE 4

Add a short care history.

Test questions

Do all needs reset?
Can one click update twice?
Can values leave the intended range?
Does the visible mood match the values?
Can the pet recover from its lowest state?

Common mistakes

Needs are never initialized.
Two scripts fight over the same state.
Values move too quickly to understand.
The pet becomes permanently stuck.

Extension ideas

Add a trust variable.
Make actions have trade-offs.
Create a day/night state.
Add a short care history.

Challenge levels

LEVEL 1

Builder

Keep two needs inside sensible boundaries.

LEVEL 2

Inventor

Make care actions affect several needs differently.

LEVEL 3

Boss Level

Create named pet states from combinations of values.

What to demonstrate

Known starting values
Two care actions
Time-based change
A visible state
A recovery path
One explained rule trade-off