[2021] pay to participate

Hello!
The folks responding are correct: The game is free to play, but not all parts of the game are free.
In this case, you have it wrong, I'm afraid.
The mission chain will be open to you as long as you have the Repulse. You can actually unlock the Repulse for FREE simply by playing through the dockyard missions.
Without paying a dime, you can unlock the Repulse for Free and begin playing the missions that require the Repulse.
You won't have as much time to complete the missions if you do it for free, but you will be able to complete them.
We try to find ways to "keep the lights on" and make the game as free to play as we can at the same time. Sometimes folks disagree with us on how well we walk that line, but it helps to keep expectations in line.
You CAN do these missions for free without paying a dime - but folks who earn the Repulse faster by putting some money towards it will be able to do them faster.
I hope that helps!