Bay 12 Games Forum

The time would be endless Bloodmoon with a greatly increased spawn rate., you'd need to make new characters, and you'd have to toss away your starting axe/pick.
Each player would get 1 copper/iron sword, 1 wooden bow, 50 wooden arrows, and 3 potions (2 incaps and one health kit).

You start on one end of a large map and your objective is to travel through the given "path" and make it to the "escape vehicle" on the other side. There could be different biomes in order to add variety as well. You could start at normal ground (zombies and demon eyes), then head underground (skeletons and worms), emerge and travel through corruption (Eater of Souls and Devourers), then have the "finale" inside of the dungeon - with skeletron already defeated of course(Dark Casters, Angry Bones, and Flying Skulls).

You'll need to pick up equipment and replenish your items along the way as the enemies get harder. You'd get some armor/weapons/ammo in each "Saferoom", but most of the time you'll come across a few (possibly hidden) chests with items you could equip yourselves with.

When placing loot, here are a couple of guidelines; you don't NEED to follow them, but it's a start.
1. No unlimited use ranged weapons - Boomerangs, Chakrums, Harpoons, etc. Ammo supply should be a constant worry.
2. No armor set bonuses - If you do include armor pieces with set bonuses, avoid placing the complete set.
3. Melee weapons should be limited to mundane metals - Melee should be a last resort option.
4. When placing items that require MP be sure to include Mana crystals and possibly MP restoration potions.
5. Since it's always bloodmoon, make sure to include torches or some form of portable lighting.
6. No placeable blocks, explosives, grappling hooks/ivy whips, or picks/axes - To prevent sequence breaking.
7. Grenades are fine, but keep in mind that one ill-timed grenade could kill the entire party.
8. No buckets.

You don't necessarily need to follow the starting item set either. If you're planning a considerably difficult run; you could set up something so each player would get a different set of items. For example, one player would get a chest with a gold broadsword, a cobalt shield, a set of iron armor, an iron bow, 50 wooden arrows, and a set of hero's vanity wear. Another would get an gold hammer, a flamelash, a flower of fire, 10 mana crystals, 2 bands of starpower, a shiny red balloon, and a set of plumber's vanity wear. Another would get an Archeologist's jacket, a pair of sunglasses, a handgun, 150 musket bullets, a silver broadsword, 20 grenades, and 2 spiky balls. And another would get a robot hat, a space gun, 5 mana crystals, an iron broadsword,  a jungle helmet, a band of starpower, and a feral claw. And another would get a silver shortsword, 100 shurikens, 50 vile powder, 2 feral claws, and a set of ninja vanity wear. Along with torches and healing potions of course.

When making saferooms, you need a room that zombies can't get into, here's an example:

To seal the door, all a player needs to do is hit the cobweb and close the door, which causes the sand to fall and keep the zombies out. In case a player hits the cobweb prematurely, other players can climb over and open the other door. If the zombies/demon eyes jump through the top door, the platform next to the sand allows you to jump high enough to close it, but not enough to get through it (Without the help of a balloon/cloud/G.hook).

Each saferoom should have some items to help players get through the next phase, whether it's ammo, weapons, or armor; that I leave to your discretion.  You can also set up a merchant and arms dealer so players could use the coins they've collected in order to supply themselves; though this could lead to abuse. Don't forget to add a bed.

Also, if you're planning on making a long path, you may want to set up "Spawn Closets" - small rooms with only a bed - so players that die don't need to go all the way back from the beginning of the section alone.

If you want to simulate timers, water/lava trapped in sand that's held up by cobwebs can act as the timer and trigger. Water would travel along the channel and de-construct any webs they come across, setting off more water/sand/etc. Cobwebs can also be destroyed by player weapons, without the need of a pick, axe, or hammer.

Setting up a timer is a bit more complicated, so here's a simplified version. (I had to edit the picture a bit since I closed the program before I realized my mistake so bear with me.)

The sand in front of us is too high for players to jump over, and without the ability to mine the sand (No picks/bombs), they're stuck. However, if you hit the cobweb on the left, the sand block falls neatly into the slot open, and the water continues along the channel and washes away the cobweb on the right, which lowers the sand wall. If you're going for a longer timer, you can use lava and make a larger drop with zigzags. Be sure to add enough liquid.

Perhaps later there may even be a "The Last Stand: Terraria Edition" map.