Really interested to see how they plan on keeping a playerbase. The combat is fairly straightforward rock/paper/scissor and storymode is completed up through lunatic. All I can do now is pull units and PvP? Seriously? No equipment, no alternate advancement, no ability to get heros you want other than orb purchase... Cmon Nintendo.
You can reroll after the tutorial and will have enough for a free 5 pull. Rerolling isn't required but it may be helpful to go for a 5* character (~27% chance). You need 4 characters at 5* for a full team which you'll probably get from free pulls a week in and will certaintly get with 4* upgrades after a month.