Arknights has been, for over 3 to 4 years now, the one satisfying and generous gacha game I have played for the longest time. Being a F2P is not entirely a problem as saving and pulling for the characters that you want aren't much of a problem. Granted, it IS a gacha game so rng is still a factor in some losses. Game progression is hardly a problem since almost all the stages/levels can be completed by just low-rarity characters. That said, potentials for characters in the game aren't exactly required as they are complimentary. They may provide some assistance but even without duplicates/potentials, the characters are ready to use. Events in the game give out a welfare/free character in which players just progress in the event to obtain, potentials included. Arknights also has some freebies here and there such as log-in events or anything the devs can throw in your mail. Limited events and yearly anniversaries are where the game gets buffed a lot with giveaways. A hefty amount of pulls and rewards are given and during CN anniversaries, a free 6-star (highest rarity) is the welfare instead of a 5-star. Skins are easily bought, granted the player saves up for said skins. Web events are also present during anniversaries, accounting for more rewards given out. I can say that most players, especially F2P, really do enjoy the game and many aspects of it. The devs are loved, the community usually goes hand in hand (most of the time), and the game itself that entertains the players and is run by people who care for its audience.