diff --git a/installer/windows/Language Files/EnglishExtra.nsh b/installer/windows/Language Files/EnglishExtra.nsh
index 4f1c4ac11..431b393f6 100644
--- a/installer/windows/Language Files/EnglishExtra.nsh	
+++ b/installer/windows/Language Files/EnglishExtra.nsh	
@@ -20,6 +20,7 @@ ${LangFileString} MUI_UNTEXT_WELCOME_INFO_TEXT "Setup will guide you through the
 ${LangFileString} GEODE_TEXT_GD_MISSING "$\r$\n$\r$\nThis path does not have Geometry Dash installed!"
 ${LangFileString} GEODE_TEXT_GD_OLD "$\r$\n$\r$\nYour version of Geometry Dash is too old for this version of Geode!"
 ${LangFileString} GEODE_TEXT_MOD_LOADER_ALREADY_INSTALLED "This path has other mods installed!$\r$\nThey will be overwritten by Geode. (the dll trademark)"
+${LangFileString} GEODE_TEXT_REGISTER_FILETYPE "Register .geode filetype"
 
 ; uninstaller
 
diff --git a/installer/windows/installer.nsi b/installer/windows/installer.nsi
index 35429bb55..b21eb1a48 100644
--- a/installer/windows/installer.nsi
+++ b/installer/windows/installer.nsi
@@ -459,6 +459,12 @@ SectionGroup "Geode"
     Section "Loader" LOADER_SECTION
         SetOutPath $INSTDIR
 
+        !define env_hklm 'HKLM "SYSTEM\CurrentControlSet\Control\Session Manager\Environment"'
+        !define env_hkcu 'HKCU "Environment"'
+
+        WriteRegExpandStr ${env_hkcu} "GEODE_GD_PATH" "$INSTDIR"
+        System::Call 'user32::SendMessageTimeoutA(i0xffff,i0x1a,i0, t"Environment",i2,i5000,i0)i'
+
         File ${BINDIR}\Geode.dll
         File ${BINDIR}\Geode.pdb
         File ${BINDIR}\GeodeUpdater.exe
@@ -480,6 +486,32 @@ SectionGroup "Geode"
         WriteUninstaller "GeodeUninstaller.exe"
     SectionEnd
 
+    Section "Register .geode Filetype" FILETYPE_SECTION
+        SectionGetFlags ${FILETYPE_SECTION} $0
+        IntOp $0 $0 & ${SF_SELECTED}
+        StrCmp $0 0 done
+
+        ; Extract the ICO to a known path
+        SetOutPath "$INSTDIR\geode"
+        File /oname=logo_inst.ico "Graphics\logo_inst.ico"
+        File /oname=installmods.ps1 "installmods.ps1"
+
+        ; Register .geode extension
+        WriteRegStr HKCU "Software\Classes\.geode" "" "GeodeFile"
+        WriteRegStr HKCU "Software\Classes\GeodeFile" "" "Geode Mod"
+        WriteRegStr HKCU "Software\Classes\GeodeFile\DefaultIcon" "" "$INSTDIR\geode\logo_inst.ico,0"
+        WriteRegStr HKCU "Software\Classes\GeodeFile\shell" "" "open"
+        WriteRegStr HKCU "Software\Classes\GeodeFile\shell\open\command" "" \
+            'powershell.exe -ExecutionPolicy Bypass -File "$INSTDIR\geode\installmods.ps1" "%1"'
+
+        ; Refresh icon cache
+        System::Call 'shell32::SHChangeNotify(i0x8000000,i0x0,p0,p0)'
+
+        SetOutPath "$INSTDIR"
+
+    done:
+    SectionEnd
+
     Section "Resources"
         CreateDirectory $INSTDIR\geode\resources\geode.loader
         SetOutPath $INSTDIR\geode\resources\geode.loader
@@ -545,6 +577,10 @@ Section "Uninstall"
     Delete $INSTDIR\GeodeUpdater.exe
     Delete $INSTDIR\XInput1_4.dll
 
+    ; Remove the .geode filetype registry keys
+    DeleteRegKey HKCU "Software\Classes\.geode"
+    DeleteRegKey HKCU "Software\Classes\GeodeFile"
+
     # default value of DATA is an empty string
     # if DATA is empty, keep user data
     # otherwise, delete the entire geode and DATA\geode\mods dirs
diff --git a/installer/windows/installmods.ps1 b/installer/windows/installmods.ps1
new file mode 100644
index 000000000..40d26fd78
--- /dev/null
+++ b/installer/windows/installmods.ps1
@@ -0,0 +1,110 @@
+param (
+    [Parameter(Mandatory=$true, ValueFromRemainingArguments=$true)]
+    [string[]]$ModFiles
+)
+
+if (-not $env:GEODE_GD_PATH) {
+    Write-Error "GEODE_GD_PATH environment variable is not set."
+    exit
+}
+
+$GEODE_GD_PATH = $env:GEODE_GD_PATH
+$MODS_PATH = Join-Path $GEODE_GD_PATH "geode\mods"
+$InstalledMods = @{}
+$InstalledOrDownloaded = @{}
+
+function Show-InstalledModsMessage {
+    param([hashtable]$Mods)
+    Add-Type -AssemblyName System.Windows.Forms
+    if ($Mods.Count -eq 0) {
+        [System.Windows.Forms.MessageBox]::Show(
+            "No new mods were installed.",
+            "Geode Mod Installer",
+            [System.Windows.Forms.MessageBoxButtons]::OK,
+            [System.Windows.Forms.MessageBoxIcon]::Information
+        )
+    } else {
+        $msg = "Installed mods:`n`n"
+        foreach ($mod in $Mods.Keys) {
+            $msg += "- $mod`n"
+        }
+        [System.Windows.Forms.MessageBox]::Show(
+            $msg,
+            "Geode Mod Installer",
+            [System.Windows.Forms.MessageBoxButtons]::OK,
+            [System.Windows.Forms.MessageBoxIcon]::Information
+        )
+    }
+}
+
+function Extract-Mod {
+    param([string]$Source, [string]$Destination)
+    if (Test-Path $Destination) { Remove-Item -Recurse -Force $Destination }
+    try {
+        Add-Type -AssemblyName System.IO.Compression.FileSystem
+        [System.IO.Compression.ZipFile]::ExtractToDirectory($Source, $Destination)
+        return $true
+    } catch {
+        Write-Error ("Failed to extract {0}: {1}" -f $Source, $_)
+        return $false
+    }
+}
+
+function Install-Mod {
+    param([string]$ModFilePath)
+
+    $ModName = [System.IO.Path]::GetFileNameWithoutExtension($ModFilePath)
+    if ($InstalledOrDownloaded.ContainsKey($ModName)) { return }
+
+    $TempDir = Join-Path $env:TEMP "temp_$ModName"
+    if (-not (Extract-Mod -Source $ModFilePath -Destination $TempDir)) { return }
+
+    $DestModPath = Join-Path $MODS_PATH ([System.IO.Path]::GetFileName($ModFilePath))
+    Copy-Item -Path $ModFilePath -Destination $DestModPath -Force
+
+    $InstalledMods[$ModName] = $true
+    $InstalledOrDownloaded[$ModName] = $true
+
+    $ModJsonPath = Join-Path $TempDir "mod.json"
+    if (Test-Path $ModJsonPath) {
+        $ModJson = Get-Content $ModJsonPath -Raw | ConvertFrom-Json
+        if ($ModJson.PSObject.Properties.Name -contains "dependencies" -and $ModJson.dependencies) {
+            Write-Host "Installing dependencies - Mod versions may be incompatible with the mod."
+            foreach ($dep in $ModJson.dependencies.PSObject.Properties) {
+                $depId = $dep.Name
+                $depValue = $dep.Value
+
+                if ($depValue -is [PSCustomObject] -and $depValue.importance -eq "suggested") {
+                    Write-Host "Skipping suggested dependency $depId"
+                    continue
+                }
+
+                $DepModPath = Join-Path $MODS_PATH "$depId.geode"
+                if ($InstalledOrDownloaded.ContainsKey($depId) -or (Test-Path $DepModPath)) { continue }
+
+                Write-Host "Downloading latest dependency $depId..."
+                try {
+                    $TempDepPath = Join-Path $env:TEMP "$depId.geode"
+                    Invoke-WebRequest -Uri "https://api.geode-sdk.org/v1/mods/$depId/versions/latest/download" -OutFile $TempDepPath -UseBasicParsing
+                    Install-Mod -ModFilePath $TempDepPath
+                } catch {
+                    Write-Warning ("Failed to download or install dependency {0}: {1}" -f $depId, $_)
+                }
+            }
+        }
+    }
+
+    if (Test-Path $TempDir) { Remove-Item -Recurse -Force $TempDir }
+}
+
+if (-not (Test-Path $MODS_PATH)) { New-Item -ItemType Directory -Path $MODS_PATH | Out-Null }
+
+foreach ($modFile in $ModFiles) {
+    if (Test-Path $modFile) {
+        Install-Mod -ModFilePath (Resolve-Path $modFile)
+    } else {
+        Write-Warning "$modFile does not exist."
+    }
+}
+
+Show-InstalledModsMessage -Mods $InstalledMods