One of the best parts of MoO was redesigning your ships after you got a significant upgrade -- a construction tech that raised your construction level enough to provide more space, a better engine, sub-space teleporters, better shields, etc. That doesn't seem to happen very much at the moment in Horizon -- all the weapons are the same barring their special effects, for example, and at the moment things don't miniaturize, so you can't fit more weapons on as your tech level goes up.
I think it would be better if there was more differentiation between the weapons -- for example, plasma cannons do more damage/space than lasers, but have the same damage/power ratio, meaning that they are effectively more power-hungry, and cost more. It would also be nice to get new weapon types that are _better_ than the early weapon types -- but maybe they would start off _less_ effective. For example, 'Hyper-collimated gamma-ray lasers' are roughly equivalent to level 5 lasers except that they have a reduced damage falloff with range, but you don't have a chance to get them until you have at least one weapon type at level 7, which means you have to raise their level a couple of times before they're as useful, and maybe they're more power-hungry at level 1 (improvement to level 2 reduces the power usage, rather than the damage, perhaps).
Another issue is that there's not enough differentiation between ship sizes given that you can't pump out more than one ship of a given size class per turn. If you can build a mothership in eight turns, and a scout-sized ship in one turn, there's not that much reason to build scout-sized ships (except for scouting); sure, they can turn faster than a mothership, but a mothership can take a lot more damage, because it can afford to have things like auto-repair, shields, etc.
In my obviously and inherently correct opinion, building a huge ship should be (and feel like!) an worthwhile achievement, at least most of the way through the game. I don't like the idea of limiting the ability to do so until you've discovered a certain tech, but I like the idea that it's not really _feasible_ until you're well established. There are a few things that I think would help with that, individually or collectively:
- Increase the difference between the size classes; instead of 20(?)/100/200/400, make it e.g. 20/200/600/1200, but increase the cost as well, meaning that even with grand-scale factories and a shipyard, the construction time for huge ships is measured in tens of turns (and, as per my comment in the other thread, don't allow a buyout to complete the ship in one turn)
- Increase the number or effectiveness of special modules on a huge ship; for example, a huge ship that's completely filled with cargo modules should be able to have more than 1.5 times the cargo capacity of a large ship, even with the current ship sizes (assuming my math is correct, you can fit 6 cargo modules on a large, and 8 on a huge, even though there's still enough space for five more cargo modules)
- Allow additional powerplants to be added, with the size based on the type of plant and size of ship
- Add an ultra-heavy mount type, which is significantly larger than a heavy, has the same damage and power cost, but provides longer range (reduces range dissipation); you couldn't fit many on a large, but can on a huge, allowing huge ships to have a range bonus. Alternatively, provide a range bonus based on ship size (you have more room for collimation/tracking computers/whatever) for regular and heavy mounts.