Features

The game

Hide, then hunt. Slashers start masked, frozen and invisible, with their screen blacked out, while survivors scatter. When the hiding time is up, their screen clears and the hunt begins.
Heartbeat. A survivor hears their own heartbeat when a slasher is close. The distance is measured on the server, so a modified client cannot use it to find the slashers.
The last survivor fights back. Shortly before a round ends, the last survivor standing is armed with the lobby's weapon.
Rounds and score. Slashers win a round by eliminating every survivor. Survivors win by eliminating every slasher, or by lasting until the timer runs out. Roles are re-picked each round, and the game goes to whoever wins the most rounds - or a draw.
Ghosts and spectating. An eliminated player's ghost stays on the map where they fell, and they spectate the surviving slashers until the round ends.
Blackout. Every round is played at midnight with the city lights off, and the weather and clock are handed back when the game ends.
Out of bounds. Leaving the map starts a countdown. Players who do not return in time are eliminated.
Native GTA Online sounds for the heartbeat, round start and end, win and loss.
Slasher outfits, set separately for male and female peds.

A full lobby browser - create, edit, delete, join, leave and join a random lobby, with a live player list. No context menus.
Password-locked lobbies. Passwords are checked on the server and never sent to a client.
Lobby settings the host picks: name, password, map, weapon, max players, max slashers, rounds, round length and hiding time. Every setting is bounded by limits you set in the config.
Routing buckets. Each game runs in its own bucket, so players in a game cannot be seen or touched by anyone outside it.

Round, countdown, survivors alive, score and the current phase. Passive - it never takes your mouse.
Scoreboard - hold TAB for the full board. A living slasher's identity is hidden from living survivors; dead players and slashers see everything.

Build maps in the world with a freecam: click to place the boundary and the spawn points, hold a key and scroll to set the zone's height as you go, undo and redo.
Edit, clone, enable, disable or delete any map. A disabled map disappears from the create-lobby list without being deleted.
Place event peds - the NPCs players walk up to - with their model, scenario, heading and map blip.
Live. A saved map or ped appears for every player at once.
Several admins at once. Each map and ped is locked to whoever is editing it.

The slasher list is never sent to living survivors.
Deaths are verified against the server's own view of the player's health.
Every lobby setting and every map is checked against your configured limits on the server, so a modified client cannot start a 999-round game or save a 50,000-point map.
The builder's permission is checked on the server on every action, not just when the menu opens.