actually theres no reason to include platforms

index.mjs

@@ -5,7 +5,6 @@ import {resolve, basename, extname, dirname, relative, join} from 'node:path';
 
 export function buildConfig ({
 	manifest: manifestPathRelative,
-	platforms = [],
 	outDir = 'build/[platform]',
 	scriptPlugins = [],
 	sourcemap,
@@ -13,10 +12,6 @@ export function buildConfig ({
 	const manifestPath = resolve(process.cwd(), manifestPathRelative);
 	const manifestDirname = dirname(manifestPath);
 
-	if (!platforms.length) {
-		throw new Error('No platforms specified');
-	}
-
 	// Load the manifest
 	let manifestContent;
 	try {
@@ -112,14 +107,11 @@ export function buildConfig ({
 
 	const {scripts, styles, assets} = getEntryPointsFromManifest(manifestContent);
 
-	return platforms.flatMap(platform => [
+	return [
 		...scripts.map(entrypointPath => ({
 			input: relative(process.cwd(), entrypointPath),
 			output: {
-				file: join(
-					outDir.replace(/\[platform\]/g, platform),
-					getOutputFilename(entrypointPath, 'js'),
-				),
+				file: join(outDir, getOutputFilename(entrypointPath, 'js')),
 				format: 'iife',
 				sourcemap,
 			},
@@ -131,10 +123,7 @@ export function buildConfig ({
 		{
 			input: manifestPathRelative,
 			output: {
-				file: join(
-					outDir.replace(/\[platform\]/g, platform),
-					'manifest.json'
-				),
+				file: join(outDir, 'manifest.json'),
 			},
 			plugins: [
 				{
@@ -172,5 +161,5 @@ export function buildConfig ({
 				},
 			],
 		},
-	]);
+	];
 }