A great trading game with few drawbacks. Buy and sell goods on the world market using your trading fleet.
You start the game with a single ship and some capital to buy some cheap cargo. Find out where you can find cheap cargo and where you can sell it. Three other companies will compete with you. There's 32 types of cargo that can be traded. But some of them can't be traded with all ships. There's also 100 harbours around the world to trade in, so in the beginning you may feel like you have no control. Trade only the most profitable cargo, stay in a limited area, or buy a specialized ship with a more limited choice of cargo. For example a bulk carrier or a refrigerator ship. Used ships can often be found cheap. Check the ship-broker once a month or so when you get money for a new ship. Buy the ship for own money, and borrow for the cargo in the bank. Alternatively go over to cheap lower profit cargo so you don't need as much in cash.
Used ships are usually a good choice, as cheap and as good as new ones. They are also quick go get, as you don't need to wait for construction plans or building times. This makes them especially good choices in the beginning when you have less money and don't want to wait for a year for your second ship. Building times for ships vary from 3 to 40 months plus the time for the construction plans to be made. The drawbacks for these ships is that you don't get exactly what you want. Short range, wrong speed, wrong wrong cargo capacity and so on. But keep in mind that the cargo is often worth twice or more the worth of the ship.
It's not possible to set up trading routes, and that is the thing that most makes larger ships interesting. You simply won't trade hundreds k of cargo every month using ships that carry only 10k or so.
When you get more ships, you may again feel that you have no control. Trading will take time, even if you only have a few types of cargo on board. Using larger ships will prevent this, but also prevent you from entering harbours, as your competitors have bought the cargo, so that there's not as much that you won't get full loads. Prevent this by buying or leasing warehouses is a good idea. But you can only fill them when you have a ship in the harbour. One method would be to use a cheap coastal freighter and visit them from time to time. But be ware that stored cargo ties up capital, so make sure you have that.
You can order own building plans. This costs money and takes some times, but are required if you want to buy a ship that have no already present construction plans. Here you can set the maximum speed, maximum cargo and maximum range.
There is some strange things in the shipyard to be found. Compare the smallest possible supertanker (gross.reg.tons: 60k, loading 150k, length 140, width 21, draught 10) with the largest possible normal tanker (gross.reg.tons: 63k, loading 120k, length 366, width 55, draught 19). Even a land lubber like me can see that this difference between ships of same weight and capacity is too big. There's some minor glitches to be found. For example, a fuel tank that are two times larger doesn't seems to affect anything but the range of the ship. Same size, same speed and same weight on the ship even with large tanks. As the fuel costs in the game is not that high, I find it best to use the highest possible speed on all ships to maximize the amount of traded goods, no matter what it is.
Another drawback is that there is no pre-defined panamax, suezmax or malackamax classes. But on the other hand, there seems to be no limits in those channels. Using bulk carriers with depth 21 m, length 394 m and width 53 m caused no problem in none of those channels. Along with the previously mentioned tanker construction glitch, this are the worst errors made in this game.
Prices in the harbours is not fixed, but it takes some times for them to change. So keeping own price lists may be smart, as it is impossible to see the prices if you don't have a ship there.
There's a stock market to be found where you can trade shares, but that's nothing I know anything about.
If you think the game is too easy or too hard there's some options to change.