diff --git a/.github/workflows/msys2-cross-compile.yml b/.github/workflows/msys2-cross-compile.yml
new file mode 100644
index 0000000..770ea3b
--- /dev/null
+++ b/.github/workflows/msys2-cross-compile.yml
@@ -0,0 +1,20 @@
+name: MSYS2
+on: [push, pull_request]
+
+jobs:
+  msys2-mingw64:
+    runs-on: windows-latest
+    defaults:
+      run:
+        shell: msys2 {0}
+    steps:
+      - uses: actions/checkout@v3
+      - uses: msys2/setup-msys2@v2
+        with:
+          msystem: MINGW64
+          update: true
+          install: mingw-w64-x86_64-gcc mingw-w64-x86_64-glib2 bison flex mingw-w64-x86_64-llvm cmake git make
+      - name: CI-Build
+        run: |
+          echo 'Running in MSYS2!'
+          ./ci-build.sh
\ No newline at end of file
diff --git a/README.md b/README.md
index faca249..daaaf32 100644
--- a/README.md
+++ b/README.md
@@ -1,17 +1,31 @@
-# Gemstone
 
-Gemstone is a programming language compiler written in C with lex and yacc.
+<div align="center">
+  <picture>
+    <img alt="gemstone logo" src="https://github.com/Servostar/gemstone/assets/72654954/fdb37c1b-81ca-4e6a-a9e9-c46effb12dae" width="75%">
+  </picture>
+</div>
+<br>
+
+## Gemstone
+
+Gemstone is a programming language compiler (short: GSC) written in C based on flex and GNU bison.
+It uses LLVM to produce optimized native binaries for many platforms and uses its own builtin build system for more complex project management.
 
 ## Dependencies (build)
 
 ### Windows 11
 
-For setup instruction see issue #30
-
-Requires:
-- Microsoft Build Tools 2022 (includes: CMake, MSVC)
-- WinFlexBison [find it here](https://github.com/lexxmark/winflexbison) (needs to be in PATH)
+#### MSYS2
 
+Install MSYS2 under Windows 11. Open the MingGW64 environment.
+Install the following packages:
+```
+pacman -S mingw-w64-x86_64-gcc mingw-w64-x86_64-glib2 bison flex mingw-w64-x86_64-llvm cmake git make
+```
+Clone the repository and build the gemstone compiler:
+```
+cmake . && make release
+```
 ### GNU/Linux
 
 Requires:
@@ -20,6 +34,8 @@ Requires:
 - Make
 - bison
 - flex
+- LLVM
+- Glib 2.0
 
 ## Writing Tests
 
diff --git a/ci-build.sh b/ci-build.sh
new file mode 100755
index 0000000..8b09b06
--- /dev/null
+++ b/ci-build.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+cmake .
+make release
diff --git a/src/ast/ast.c b/src/ast/ast.c
index 1381331..a9c1af6 100644
--- a/src/ast/ast.c
+++ b/src/ast/ast.c
@@ -215,6 +215,7 @@ void AST_delete_node(struct AST_Node_t *node) {
     DEBUG("Deleting AST node: %p", node);
 
     if (node->parent != NULL) {
+        [[maybe_unused]]
         const struct AST_Node_t* child = AST_detach_child(node->parent, node);
         assert(child == node);
     }
diff --git a/src/io/files.c b/src/io/files.c
index 9ca0a93..ecb2662 100644
--- a/src/io/files.c
+++ b/src/io/files.c
@@ -14,9 +14,15 @@
 
 #define MAX_PATH_BYTES PATH_MAX
 
+#define min(a, b) ((a) > (b) ? (b) : (a))
+
 #elif defined(_WIN32) || defined(WIN32)
 
 #include <Windows.h>
+// for _fullpath
+#include <stdlib.h>
+// for _mkdir
+#include <direct.h>
 
 #define MAX_PATH_BYTES _MAX_PATH
 
@@ -66,10 +72,6 @@ void delete_files(ModuleFileStack *stack) {
 // seeking the current line in print_diagnostic()
 #define SEEK_BUF_BYTES 256
 
-static inline unsigned long int min(unsigned long int a, unsigned long int b) {
-    return a > b ? b : a;
-}
-
 // behaves like fgets except that it has defined behavior when n == 1
 static void custom_fgets(char *buffer, size_t n, FILE *stream) {
     if (n == 1) {
@@ -123,15 +125,15 @@ void print_diagnostic(ModuleFile *file, TokenLocation *location, Message kind, c
 
     mem_free((void *) absolute_path);
 
-    const size_t lines = location->line_end - location->line_start + 1;
+    const unsigned long int lines = location->line_end - location->line_start + 1;
 
-    for (size_t l = 0; l < lines; l++) {
+    for (unsigned long int l = 0; l < lines; l++) {
         printf(" %4ld | ", location->line_start + l);
 
-        size_t chars = 0;
+        unsigned long int chars = 0;
 
         // print line before token group start
-        size_t limit = min(location->col_start, SEEK_BUF_BYTES);
+        unsigned long int limit = min(location->col_start, SEEK_BUF_BYTES);
         while (limit > 1) {
             custom_fgets(buffer, (int) limit, file->handle);
             chars += printf("%s", buffer);
@@ -169,13 +171,13 @@ void print_diagnostic(ModuleFile *file, TokenLocation *location, Message kind, c
     }
 
     printf("      | ");
-    for (size_t i = 1; i < location->col_start; i++) {
+    for (unsigned long int i = 1; i < location->col_start; i++) {
         printf(" ");
     }
 
     printf("%s", accent_color);
     printf("^");
-    for (size_t i = 0; i < location->col_end - location->col_start; i++) {
+    for (unsigned long int i = 0; i < location->col_end - location->col_start; i++) {
         printf("~");
     }
 
@@ -321,7 +323,7 @@ const char *get_absolute_path(const char *path) {
 #elif defined(_WIN32) || defined(WIN32)
     // use Windows CRT specific function
     char absolute_path[MAX_PATH_BYTES];
-    _fullpath(path, absolute_path, _MAX_PATH);
+    _fullpath((char*) path, absolute_path, _MAX_PATH);
 #endif
 
     return mem_strdup(MemoryNamespaceIo, absolute_path);
diff --git a/src/io/files.h b/src/io/files.h
index 61c7ebb..c05f587 100644
--- a/src/io/files.h
+++ b/src/io/files.h
@@ -15,9 +15,9 @@
 #endif
 
 typedef struct FileDiagnosticStatistics_t {
-    size_t error_count;
-    size_t warning_count;
-    size_t info_count;
+    unsigned long int error_count;
+    unsigned long int warning_count;
+    unsigned long int info_count;
 } FileDiagnosticStatistics;
 
 typedef struct ModuleFile_t {
diff --git a/src/sys/col.c b/src/sys/col.c
index 76260ec..afd78ba 100644
--- a/src/sys/col.c
+++ b/src/sys/col.c
@@ -71,8 +71,7 @@ int stdout_supports_ansi_esc() {
   HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
 
   if (!GetConsoleMode(hConsole, &mode)) {
-    ERROR("failed to get console mode");
-    return ANSI_ENABLED;
+    return ASNI_DISABLED;
   }
 
   if ((mode & ENABLE_VIRTUAL_TERMINAL_INPUT) |