Note: I originally hand-wrote this review during a really boring meeting! It's probably a bit rough, but the essential theme should be there. I ran this scenario at low tier using the four-player adjustment.
The First Mandate is a great scenario for Starfinder players who are looking for a role-play heavy experience. It's perfect for skill monkeys, with combat taking a backseat. There are some great, well-fleshed out NPCs, though admittedly the plot is pretty basic. I'd recommend it as an opportunity for non-combat oriented characters to shine.
The centrepiece of The First Mandate is a major gala at Starfinder Society headquarters. First Seeker Luwazi Elsebo has invited several guests with powerful connections to hear a major announcement about the future direction of the organization. The PCs are asked to persuade some of these major players to lend their support (both moral and financial) to the SFS. In game terms, this takes the form of an RP-heavy skills challenge, where the PCs are given a set number of opportunities to influence five different NPCs. Each of the NPCs has an interesting and memorable personality with their own interests and ways of being persuaded. It's not all Diplomacy, as skills as diverse as Acrobatics to Medicine can be used to impress certain NPCs. (I appreciated the full-colour artwork of the NPCs, and recommend GMs use the pictures to help the players remember who they're interacting with each round.) I thought this "social encounter" was a really clever way to get everyone involved in the teamwork necessary for success, and it's always fun to role-play a fancy, formal gala when most PCs are going to be hulking vesks or carrying an armory's worth of weaponry. The coolest thing is that the particular NPCs that are influenced take part in events later in the scenario.
After this RP-intensive encounter, the PCs are approached by Radaszam, head of the Acquisitives faction, with news that a potential assassin has been traced to a warehouse in the Sparks neighborhood of Absalom Station. The PCs, of course, are sent to raid the warehouse. They won't find an assassin, but (after probably setting off a nasty trap) will do battle against a pair of creatures called "electrovores" and then find clues that point to the assassin being a shapechanger who plans to set explosives to kill Luwazi Elsebo! It's not the most creative encounter (the electrovores are kinda run-of-the-mill and are present more because combats are expected in scenarios), but it does advance the plot.
After the PCs rush back to the gala, a really fun and tense encounter begins. The PCs can play it safe by having Radaszam's mercenary outfit take care of finding/defusing the bombs or the PCs can take the riskier (but more impressive to the dignitaries) strategy of handling both the bombs and the assassin at the same time. It's a delicate balance, because one misstep leads to the assassin pressing that detonator button, and it would be quite easy for the PCs to fail magnificently. The group I ran this for succeeded as much through luck as strategy.
Assuming the PCs are successful in stopping the bombs and the assassin, the end of the scenario is a bit of a let-down. There's no explanation as to why Luwazi was targeted, whether the assassin was hired or acting alone, etc. And more, Luwazi's big announcement (that she's going to try to solve the "Scoured Stars" problem and recover the lost Starfinders) isn't exactly a big surprise. It comes off as anti-climactic given all the work put into supporting the effort and saving Luwazi's life.
All in all, though, I thought The First Mandate was a solid scenario. It's a nice change of pace, with a great social encounter and an original encounter combining skills and combat. It's not a scenario that will find great favour with the "combat combat combat" crowd, but for most others it should be a satisfying experience.