This is such an amazing game which I couldn't have more fun for years, so I decided to leave some of my feedback (as a new player never played such "sandbox" like games before) to devs and hope the game will get better and better.
Most of my feedback will depend on my ~450 hours of game play and focus on late game stage. By any means it is not a criticism of the game. 450 hours! For the games I usually played a lot, like Path of Exile, 450 hours will have me finish all the season contents and have couple mirror tier gears, and I would probably already quit the season and wait for the new season to begin.
Feedback 1: The endless research
The endless research currently serves as the only way to consume the production from my factories. However, some of the research has no purpose. For example, increase player health (need in early game but not late game). The railgun attack speed (limited by animation), the railgun damage (they already one-shot everything).
Feedback 2: Make promethium more useful
Promethium is the most difficult to obtain resource in the game and currently, the only product it can make is the black research bottle, and the only research needs black bottle is the research productivity. I have just finished research productivity lvl 42 and lvl 43 will need 2.4M of all the bottles and increase my biolab productivity from 510% to 520%. I start to feel unworthy spending more resource and time on it because I can't feel any difference unless I move my mouse pointer to the biolab and read these numbers.
I hope the game can provide more ways to use Promethium. Maybe link with quality like this mob does? https://mods.factorio.com/mod/promethium-quality
Or simply add a new type of floor with 160% walk speed that made of Promethium
Feedback 3: The quality system
The quality system is cool but feels unbalanced. Some of the quality upgrades are very strong like Mech Armor, Spidetron, Asteroid grabber. Some of them are less exciting like Nuclear/Fusion reactors due to not saving fuels. Some of them have completely no effect except HP like locomotive, cargo wagon, liquid storage, agricultural tower. I hope there's a better balance of the qualities and makes every quality item useful.
Feedback 4: The endgame
This may be combined with previous points. I stopped growing my factories after I don't feel the upgrade from endless research and my only activity in game now is making new space platforms. I hope the game can provide more ways to play at the endgame, to consume all the products from factory other than all turn into bottles and burn in labs. Someone may say defense your base from the biters, but with legendary artillery turrets and spidetrons, they don't stand a chance.
Wish everyone a happy new year!
