Sway complexity of upper playfield ship:
It looks like ship only rotates from side to side around one rotation point which is OK (I'm guessing two dimensional swaying was not worth the effort although would have been cool).
Regarding this swaying motion, I have seen that it has different rates of sway depending on gameplay and Eric mentioned in release vid that he intends to have more sway occurring than what is seen now. Naturally these sways should be based on sine waves and not on linear side-to-side motions.
Cannon shot from ship should be more difficult to make the further you get into the game. Early and easier modes have little sway or more predictable sway so shot is easier. Highest levels (wizard modes etc) should require almost wizard levels of skill to succeed at this cannon shot. I say this as it is very easy to release a game where after playing only a few games, most people will get the shot a high percentage of the time and this would be a shame as it would devalue the importance of that shot in the game.
Sway action should not just increase in speed as a way to make shot more difficult but should incorporate more complex motions like the following:
a) Lowest levels only increase speed of sway to make shot more difficult (single sine wave action - very predictable).
b) Intermediate levels add multiple sine waves of differing frequency to make sway more difficult to predict. Sine waves are low-integer multiples of other waves so that they line up every few waves (so they are ultimately still predictable with practice). So you might have one sine wave at frequency x and the other at 0.5x for example (then 1/3, 1/4, 2/3 etc).
c) Higher levels may incorporate 3 or more sine wave making it seem almost random but still not random with enough practice (integer multiples again like 1:2:3, 1:2:4 etc.). Even higher levels can then incorporate non-integer multiples of sway frequency so would seem random. And ultimately at highest wizard levels, incorporate some random sine frequencies to get crazy sway and make it very difficult and almost unpredictable (just like what it would seem like during crazy storm on ocean).
((d)) Crazy wish if possible, start to incorporate 2d waves at highest levels so ship can sway forward and back as well as side to side but I understand this is probably too difficult and it's too late to change hardware.
I should add that amplitude of wave should also be scaled up as difficulty increases (so maximum sway occurs at highest levels of course).
Here is 2D simulation using 5 sine waves:
Also, although most sways should be generated by sine waves to model how real waves work, during special modes it would be cool to break this with violent shaking or other motions occasionally during a Kraken attack or whatever.
In any case, in plain English, what I'm saying is that it would be cool to make the ship shot an increasingly difficult shot to make depending on game level and at highest wizard level should be at least as hard as hole-in-one shot in No Good Gophers. Most importantly to make the ship **a minigame-like game** that requires development of skills in and of itself - you have to play a lot to get better at this shot.