Algodoo

W and S to speed up/slow down
A and D to turn
Black bar near the bow acts as an indicator of your speed
Mouse to aim
Shift to toggle firing cannons.
Q to switch weapons.

Comes with a demo level.

Changes:
Rather than shoot, shift toggles shooting. That means that for more repetitive tasks,
you only need to aim and turn (rather than holding shift and w).

Q to switch weapons. The pip on the battleship bridge displays the active weapon
(black for long-range cannons, white for short-ranged machine guns).

...

Do leave suggestions, I need ideas.