I worked out the bank system at least partly; the bills still need to be computed, and I need some way to handle what happens when you are owing some money. I am thinking property seizure.
I have played the game through to the point where you get to the Galactic Senate without any problems, and can purchase your first new ship. The game seems playable. I of course am implementing "helps" along the way, as much as I can. For instance there are now ATMs to deposit/withdraw money into your Galaxy Credit account. Likewise, you can access the ship database (for seeing what ships to buy) through CommLink, once you have visited the Ministry of Transportation.
I guess of things that are left, I'd like to implement the ministry of war, which is basically the same as transportation except it helps you to find weapons to buy. I need to finish working out the ship licencing. I also need the ministry of economies, which can provide information (for a price) on various commodities. The commodity price tracker itself needs to be reworked a bit. I'm thinking, for any commodity, it can show you the top 10 buyers and lowest 10 sellers, rather than just the top one of each. This should make it a lot more useful when you need to make trades, without really complicating things. Admittedly, this one tool is a bit unweildy and probably would be nicer if it had a custom GUI but, that's unfortunately not very likely.
What else. I need to work up the training system, but I may put that off for a bit. You have to train your piloting skills, and also your language skills. Right now you can get licences but you still have to find a piloting trainer to actually improve your skill (it's a 2-step process: 1- find the trainer and pay EXP to learn, 2- take the examination to improve your ability). I need to provide language trainers for the minor cultures (major cultures have a fairly simple method for learning the language). And then this of course all has to be balanced.
So I think I will just work on getting these bits and pieces fleshed out this week. They are all more or less neccesary, none of them is too hard, and they support the core gameplay (rather than represent new features) so in the end, they will hopefully move me towards my eventual goal of being able to level up properly and finish the game.
Speaking of balancing, I have done quite a bit of work on that. What I found was most useful was just to plot some graphs of the damage-per-second, hitpoint, etc. functions against each other to try and get an idea. Overall, it should be balanced and so far as I have played it seems to be. If you are truly an amazing pilot, you can kill monsters say 10 or 15 levels higher but it's very difficult. Monsters around your level seem to be more or less easy pickings, but they can occasionally give some troubles. And monsters of lower level usually die to one or two hits. This will ramp up in difficulty once I get more monster special attacks in. It remains to be seen how interesting that is in the end, but I think that it will actually be pretty fun.