Tap the colour of the letters, not the word. Hit the target before the clock runs out and time comes off your lock. Fall short and every right answer goes on it.
Tap the colour the word is printed in. RED means tap blue.
With the INK / WORD rule, the label above the word says which one counts.
A wrong tap costs 3 seconds.
The bill grows with every right answer. Only reaching the target wipes it.
Test game: free to play, nothing is paid and your lock doesn't change.