I'm glad you think it looks promising, and I thank you very much for the feedback!
- The starting state has been remedied with a boost in movement speed, and a starting island for your own choice of upgrades.
- Audio will be implemented eventually, but it might take a little while.
- A cannon cooldown indicator is also planned, and hopefully it won't be long until it's available.
- A tutorial in general is of low priority, as this game isn't meant to reach a large audience; almost everybody that's played it has had immediate access to a developer. But an image based guide is now planned.
- Upgrade explanations will be implemented somehow, and would potentially be a part of the previously mentioned guide. But a price display is now available.
- The gold coin was just there for visual flare (Oskar insisted). The health bar is meant to display people, your crew, not ships. But I do agree that the HUD icons might be a little confusing and could use a redesign. For now I've simply tried to amend the plank inconsistency, by removing any mentions of healing; as you stated, the planks are meant to represent reparation.
TL;DR: Thank you for your feedback!
The starting state has been improved.
Audio, and a cooldown indicator are both planned.
A guide -- to help new players -- will eventually be added.
Upgrades will be explained somehow, and a price display is now available.
Some icons might be confusing, and will hopefully be redesigned.