This has huge potential and serious balance problems.
The good: The visual style is great. The controles take some getting use to but are functional. The music is good and fits the theme of the game (Though a little repetitive). The mix of different missions is good and the idea of slowly upgrading is also good. As you become more wanted, more enemies appear and they slowly become more difficult.
The world is randomly generated and the difficulty of different enemies makes for a variety of gameplay.
The bad: For a game to be great we have to think about how our decisions. Being an open world game you as the player have the choice of when to engage. If you don't want to take the fight to the enemy, you don't have to. This would be great if the upgrade system was closer matched with the risk/rewards.
Good Example: Mission: Destroy three rocks. Difficulty (tutorial/easy) get use to flying and shooting. The reward for the rocks is 1-3 gold. The mission once complete will then reward you with 15 gold (or worth of items).
This is a great mission; if you get caught in the after explosions of the rocks you'll need the 15 gold just to reful and repair. If you are good at this mission you will ony need to refule and your up 10-12 gold. The the return is a great positive.
Bad example: Mission: Destroy two crusers. Difficulty (medium/hard) You need to engage ships with superior fire-power and health. In addition, aonce you gain a wanted level for destroying a ship: other ships, and structures will start gunning for you. This will continue untill you pay the corruption fee to get them off your back or complete the mission. This mission is slightly cost effective. Each cruser is worth 100 gold, but you will easily pay 80 to refule and repair. I had to mine rocks untill I had both upgraded guns (200 total cost) to be able to engage them. I also spent about 20 gold worth if missles to take them and my persuers down. The reward for the mission was a pretty trivial number of bombs.
The effort of the mission did not reflect the reward. Additionally I felt after I had upgraded my guns, the real fire power was in consumable missles and bombs. Buying armour and extra fule was just a waste of money.
Overall:
With an open world you want to feel like your choices matter. With an upgrade system you want to feel that you will eventually become better than your foes. In this game you feel like that is achieveable, but only if you mine rocks for 20 hours.
How to fix it:
The key part of this needs to be the gradeation. As soon as you become wanted level 1 friendly bases start shooting down hostiles. But every hostile shot down increases your wanted level. This means that the longer you stay near friendly bases, the higher your wanted level will become. This feeling of being either the most wanted freedom fighter in a galactic war, or just some rock miner is what is turning people away from the game.
By stepping this out. E.g. Make the wanted system out of 100. Cargos and interceptiors add 1, cruisers add 8, bunkers add 15, ... up to the alien ship that adds 80. Make the level of wantedness meaningful. HQs won't fire at you if your wanted is anything less than 40. Cruisers will take the occasional post shot if your wanted is higher than ten but wont fire at full speed untill it passes 30 and they will hold back on the homeing missles untill your wanted level breaks 70. These are just rough numbers, but hopefully the idea is clear.
I love the fact that the updates are making this better, keep it up. I hope to come back in a couple months to a 5 of a game.