I thought the ship was quite fun to control, it did feel quite out of control though.
The main thing I felt was missing was any kind of penalty for failing to control the ship. The game didn't present any challenge (since you could bounce around for ever). But at the moment if you penalised the player for not controlling well it would feel unfair.
Possibly if you gave the player more control but offset that with a damage penalty for hitting the wrong stuff?
The boost Probably needs to ramp over time, instead of being instantaneous, I think it might be better if the ship controlled more like a lander ship (without the gravity) so the ship keeps more of its inertia and the thrust was weaker and the player could do it more gradually?