There are over 350 of them, just as the developer said in its descriptive blurb. But if you want to keep leveling up and making your city prosper to the best of your ability, you’ll want to follow the in-game quests as the game advises you to. You can do this by going to the top left part of the main screen and checking the tasks. These may include putting up buildings or having contracts, and these quests will allow you to net some additional rewards.
Heading to the residential building store allows you to check if there are new types of residences you’ve just unlocked. Building one of these houses would allow you to unlock more workers, thus giving you more manpower to take care of more tasks simultaneously.
If you ever do not have any more space to put up buildings despite clearing everything that you can clear out, Maritime Kingdom will allow you to sell materials or keep them in your storage. This would be especially useful if you’ve got too much decorations than what is required by the quest you have taken.
Crystals are Maritime Kingdom’s premium currency and you can normally get them by completing quests. You can also use real money to buy more crystals, but you ideally wouldn’t want to do this, right? Instead of spending your hard-earned dough, you can alternately look for free crystals in treasure chests. There’s no guarantee you’ll get crystals in there, but it’s always worth a try – even if you don’t get crystals, these chests come with their share of neat freebies.
Once you’ve got yourself some crystals, you don’t need to spend them right then and there. In fact, it would be foolhardy to purchase something with them right away. What you don’t want to do is to use crystals to pay for a temporary upgrade; instead, use them for permanent upgrades like expansions.