Always check before pulling the trigger to see what sort of ragdoll you will be firing out of the canon you are using as the type of ragdoll you fire depends on the canon.
Hidden Buttons
Keep an eye on the upper-edge of the screen as some of the buttons are hidden there.
High Scores
An easy way to get high scores is to replay levels, you can replay levels at any time.
Various Gameplay Hints
Some buttons are hidden in the upper-edge of the screen, so keep an eye out for them.
You can replay the levels at any time if you want to get the high scores.
The sort of ragdoll you fire depends on the sort of cannon you're using, so make sure you check before you pull the trigger.