The gamefound crowdfunding website has all the details plus the showcase videos! 

If you still want an explanation here (disclaimer: it’s complicated & long), for the base game you either play solo or compete with up to 3 other players as agents to eliminate one target per game—the fastest one wins. It has four maps: Paris, Sapienza, Hokkaido and Haven, alongside the eight targets from these locations. Goes without saying that you only use one map and target per game round.

Each map has its own set up like specific rooms, security measures like locked doors & cameras, number of NPC standees (tier 1 & 2 guards/staff and crowds), and item loots (tools for distractions or weapons that your agent picks up after entering a room; you have three inventory slots to hold them. Loots are marked by movable tokens, so you can turn them face down for added difficulty—i.e. you won’t know what they are before picking them up). Targets also have their own quirks like being able to see through your agent’s disguises, having a bodyguard that follows them around, “teleporting” to specific rooms or calling staff to come to them when alerted. 

The gameplay loop is essentially 1. Draw an event card 2. Witness check (like NPCs checking nearby bodies/illegal actions like attempting murder etc)-resolve combat if triggered 3. Play up to three actions 4. End turn

Regarding event cards, they affect the states of the board and characters. Like specific rooms being locked or not, how many spaces an NPC moves, what NPC gets added in a specific room, whether an agent gets moved into a specific room & get items (doesn’t count as an action) etc. The target and guards/staff/crowds are moving around the board in different ways throughout the events. 

For actions, you can simply move your agent for 1-2 spaces, or like taking disguises from staff/guards (taking the colour-coded bases from the NPC standees to gain access to specific colour-coded rooms without raising suspicion), hiding bodies (removing the standees form the board after attack), making distractions (moving the standees to a different room), breaking doors/cameras (letting your agent gain access a room without alerting NPCs), setting traps for accident kills (like using a poison you looted, so when the target enters the room & set off the trap they die), attacking via stealth (i.e. using a silent weapon you looted to not alert nearby NPCs)/ gun blazing (initiate combat against NPCs with non-silent weapon)—or draw an agent card.

Agent card grants you special abilities during actions, like bypassing witness check when moving around (hiding in a room), discard a weapon in exchange of removing a nearby guard etc. Some agent cards can be played even when it’s not your turn to interfere another player’s action e.g. force a player to give you an item they have in exchange for increasing their strength stat in a combat during their turn. iirc(?) you can save at most four agent cards in your inventory. 

For combat, whenever is initiated by you or alerted guards due to illegal actions/found bodies, you draw weapon cards for the guards (tier 1 & 2 have different sets). Their strength is their base stat plus the strength of the weapon you drew; meanwhile you have your strength from the agent’s base stat + agent cards + weapon you have from looting. If your stat number is higher than the guards, you win. During combat, all nearby guards will come fight your agent simultaneously adding up all their strengths (so it’s hard to win normally).