The most unassuming, lowkey empire I've ever done.
With well over 3000 development, and every island province under my direct control (except for the Iceland which is owned by my vassal Norway). I completed the "Empire of Mann" achievment. It doesn't look much to the world on the map, but even though I sport global naval dominance and troops everywhere my monthly balance is 800 gold/month.
Released as a vassal of England and the start. After my independence i turned into a pirate republic and was from there on out economically safe (raiding the English channel has some insane value). The first 100 years or so was dedicated to eating the british isles, and turning on Denmark to get access to the Lübeck trade node (more raiding). In the first war I also took one Norweigan core (they had been integrated) and released for cheap reconquest since I, at that time, had quite a problem with AE.
Eventually I managed to ally Aragon and Austria, which I kept as friends for a very long time. Around late 1500 I set my eyes on the world, colonising the Carribean and islands around Africa. When I got my trade companies set up on Madagascar I was pretty much too powerful to be stopped and it was basically just a question of how fast I could conquer and colonize.
2 things markedly slowed me down. First of all, colonising. There are alot of uncolonised provinces and since I had pretty much monopolized colonization in the old world by taking the islands, the AI couldn't help me that much since they lacked ranged for a long time. During late 1600 i was spending about 700 ducats a month just on colonial maintence. Second, I had a hard time finding all the islands since clicking on the achivement always brought me to the same island I lacked so I had to take it before I could find the next one I needed. Since I was a republic and stability cost is high, i decided to speed 5 it and wait for truces to run out.
I kept my capital on the province of Mann which hinderd me from being the spawning point of both industrialization and the enlightenment and as I usually do when going for an achivement I mostly kept to what the achivement demands (not every game has to be a WC and RP is fun). The only exceptions here being the Cape (free merchant) and Canton (was planning on making a client state until I realised it couldn't be done with oversees provinces).
All in all, a fun achivement, however not too hard I would say. The inital challange is by far the hardest and once you got the british isles under control, you will probably have it quite easy being rich and powerful.