Vertical Drop Heroes HD — Setup Guide

Windows only. The game has no Linux build (Proton should work but is untested), and while it does ship a macOS build, gm-apclientpp publishes no macOS binary, so there is nothing to load there yet.

Do I need a client?

No. The Archipelago client is compiled into the game itself, so there is no separate client process to run — set up a Slot once, then choosing Single Player connects you.

A text client is still useful for chat, !hint, and release commands, but nothing about items or checks depends on it.

Installing

You need Python — https://www.python.org/downloads/, and during setup tick "Add python.exe to PATH". Nothing else: UndertaleModTool and gm-apclientpp.dll are inside the patcher zip.

1. Copy your whole game folder somewhere outside Steam and work on the copy. Steam can "verify" your real install and quietly undo everything.
2. Extract vdh-ap-patcher.zip into that game folder.
3. Double-click patch.bat.

You should end up with this, and nothing to type:

Vertical Drop Heroes HD\
    data.win
    Vertical Drop Heroes HD.exe
    gm-apclientpp.dll        <-- from the zip
    patch.bat
    build\
        build.py
        utmt\UndertaleModCli.exe
    gml\
    third-party\             <-- licenses, and UTMT's GPL source

The patcher needs no configuration because it is sitting in the folder it patches. If you would rather keep it elsewhere, set VDH_GAME_DIR to the folder holding data.win and run python build\build.py.

Installing the apworld

Drop vertical_drop_heroes.apworld into your Archipelago install's custom_worlds/ folder. Only the person generating the multiworld needs it.

Launch the game, go to Game Options → Archipelago, fill in Server and Slot, and choose Connect. Ctrl+V pastes. After that, picking Single Player connects for you automatically.

Leave Slot empty and the mod stays completely dormant: it never even loads the DLL, and the game plays as vanilla.

Connecting

Launch the game and go to Game Options > Archipelago.

Server:    archipelago.gg:38281
Slot:      YourSlotName
Password:  (leave empty if the room has none)
Connect
Back

Up/Down moves, Enter edits a field or activates a row, Ctrl+V pastes, Esc goes back. Fields are saved as you leave them, so the details persist across restarts, and Connect can be used again at any time to retarget a different server without restarting the game.

You do not have to press Connect: if a Slot is filled in, choosing Single Player connects automatically as the run starts. The mod deliberately does not connect at launch, so the server's checked-location set never lands on top of a session already in progress.

Status is shown live on that page, and as a small readout in the top-left during play: connecting -> handshaking -> connected.

Everything is still written to archipelago.ini, so you can edit that by hand instead if you prefer -- but note that it is not the copy in your game folder. GameMaker redirects the game's file writes into its own save area, which for this mod is %LOCALAPPDATA%\Vertical_Drop_Heroes_HD\. The Options page prints the exact path on its bottom line, and ap_debug.log is in there too. Editing the copy sitting next to the exe has no effect.

Leaving Slot empty keeps the mod completely dormant -- it does not even load the DLL, and the game plays as vanilla.

What changed in the game

• The Merchant sells unlock purchases rather than specific skills. A Merchant standing on level L fills one of that level's five slots -- level 1's five are on level 1, and only there. Once a level's five are taken, its Merchants have nothing left to sell. The traits and powers themselves arrive as Archipelago items.
• Every shop shows what you are buying. The Blacksmith, Apothecary, Monk and Merchant each display the actual item sitting on their next location, including whose world it belongs to.
• Blacksmith / Apothecary / Monk likewise check a location per purchase; your damage, max HP and orb XP levels are driven entirely by the Progressive Damage / Progressive Max HP / Progressive Orb XP items you receive. Each stops selling once all its tiers are checked.
• Shortcut crystals check a location and still cost coins to enable, so lighting one is a real trade-off against shopping. Progressive Shortcut items are what actually raise how deep you can start, and using a shortcut you already own is free.
• Clearing a level (taking its exit portal, by boss or by keys) checks a location, for levels 1–10.
• Defeating the Chosen One is the goal.

Because the server replays your whole item list on every connect, reconnecting mid-session restores your unlocks and upgrades exactly.