diff --git a/gnu/packages/games.scm b/gnu/packages/games.scm
index f6237cf1c18..c4b58c39700 100644
--- a/gnu/packages/games.scm
+++ b/gnu/packages/games.scm
@@ -5030,63 +5030,62 @@ modes.")
   (package
     (name "unknown-horizons")
     (version "2019.1")
-    (source (origin
-              (method url-fetch)
-              (uri (string-append "https://codeload.github.com/unknown-horizons/"
-                                  "unknown-horizons/tar.gz/" version))
-              (file-name (string-append name "-" version ".tar.gz"))
-              (sha256
-               (base32
-                "1n747p7h0qp48szgp262swg0xh8kxy1bw8ag1qczs4i26hyzs5x4"))
-              (patches (search-patches "unknown-horizons-python-3.8-distro.patch"
-                                       "unknown-horizons-python-3.9.patch"
-                                       "unknown-horizons-python-3.10.patch"))))
-    (build-system python-build-system)
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append "https://codeload.github.com/unknown-horizons/"
+                           "unknown-horizons/tar.gz/" version))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32 "1n747p7h0qp48szgp262swg0xh8kxy1bw8ag1qczs4i26hyzs5x4"))
+       (patches (search-patches "unknown-horizons-python-3.8-distro.patch"
+                                "unknown-horizons-python-3.9.patch"
+                                "unknown-horizons-python-3.10.patch"))))
+    (build-system pyproject-build-system)
     (arguments
-     '(#:phases
-       (modify-phases %standard-phases
-         (add-before 'build 'set-HOME
-           (lambda _
-             (setenv "HOME" "/tmp")
-             #t))
-         (add-after 'build 'build-extra
-           (lambda _
-             (invoke "python3" "./setup.py" "build_i18n")
-             (invoke "python3" "horizons/engine/generate_atlases.py" "2048")
-             #t))
-         (add-after 'install 'patch
-           (lambda* (#:key outputs #:allow-other-keys)
-             (let ((out (assoc-ref outputs "out")))
-               (substitute* (string-append out "/bin/unknown-horizons")
-                 (("os\\.chdir\\(get\\_content\\_dir\\_parent_path\\(\\)\\)")
-                  (string-append "os.chdir(\""
-                                 (assoc-ref outputs "out")
-                                 "/share/unknown-horizons\")"))))
-             #t))
-         (add-before 'check 'fix-tests-with-pytest>=4
-           (lambda _
-             (substitute* "tests/conftest.py"
-               (("pytest_namespace")
-                "pytest_configure")
-               (("get_marker")
-                "get_closest_marker"))
-             #t))
-         ;; TODO: Run GUI tests as well
-         (replace 'check
-           (lambda _
-             (substitute* "horizons/constants.py"
-               (("IS_DEV_VERSION = False")
-                "IS_DEV_VERSION = True"))
-             (invoke "pytest" "tests")
-             (substitute* "horizons/constants.py"
-               (("IS_DEV_VERSION = True")
-                "IS_DEV_VERSION = False"))
-             #t)))))
+     (list
+      #:test-flags
+      ;; 'tutorial' scenario not in the database.
+      #~(list "-k" (string-join (list "not test_start_scenario_by_name"
+                                      "test_start_scenario_by_path")
+                                " and not "))
+      #:phases
+      #~(modify-phases %standard-phases
+          (add-before 'build 'set-HOME
+            (lambda _
+              (setenv "HOME" "/tmp")))
+          (add-after 'build 'build-extra
+            (lambda _
+              (invoke "python3" "./setup.py" "build_i18n")
+              (invoke "python3" "horizons/engine/generate_atlases.py" "2048")))
+          (add-after 'install 'patch
+            (lambda _
+              (substitute* (string-append #$output "/bin/unknown-horizons")
+                (("os\\.chdir\\(get\\_content\\_dir\\_parent_path\\(\\)\\)")
+                 (string-append "os.chdir(\""
+                                #$output "/share/unknown-horizons\")")))))
+          (add-before 'check 'fix-tests-with-pytest>=4
+            (lambda _
+              (substitute* "tests/conftest.py"
+                (("pytest_namespace")
+                 "pytest_configure")
+                (("get_marker")
+                 "get_closest_marker"))))
+          ;; TODO: Run GUI tests as well
+          (replace 'check
+            (lambda args
+              (substitute* "horizons/constants.py"
+                (("IS_DEV_VERSION = False")
+                 "IS_DEV_VERSION = True"))
+              (apply (assoc-ref %standard-phases 'check) args)
+              (substitute* "horizons/constants.py"
+                (("IS_DEV_VERSION = True")
+                 "IS_DEV_VERSION = False")))))))
     (inputs
-     `(("fifengine" ,fifengine)
-       ("python:tk" ,python "tk")
-       ("python-pillow" ,python-pillow)
-       ("python-pyyaml" ,python-pyyaml)))
+     (list fifengine
+           (list python "tk")
+           python-pillow
+           python-pyyaml))
     (native-inputs
      (list intltool
            python-distro
@@ -5094,21 +5093,22 @@ modes.")
            python-greenlet
            python-polib
            python-pytest
-           python-pytest-mock))
+           python-pytest-mock
+           python-setuptools))
     (home-page "https://unknown-horizons.org/")
-    (synopsis "Isometric realtime strategy, economy and city building simulation")
+    (synopsis
+     "Isometric realtime strategy, economy and city building simulation")
     (description
      "Unknown Horizons is a 2D realtime strategy simulation with an emphasis
 on economy and city building.  Expand your small settlement to a strong and
 wealthy colony, collect taxes and supply your inhabitants with valuable
 goods.  Increase your power with a well balanced economy and with strategic
 trade and diplomacy.")
-    (license (list
-              license:gpl2+        ; Covers code
-              license:expat        ; tests/dummy.py, ext/polib.py
-              license:cc-by-sa3.0  ; Covers some media content
-              license:cc-by3.0     ; Covers some media content
-              license:bsd-3))))    ; horizons/ext/speaklater.py
+    (license (list license:gpl2+        ;Covers code
+                   license:expat        ;tests/dummy.py, ext/polib.py
+                   license:cc-by-sa3.0  ;Covers some media content
+                   license:cc-by3.0     ;Covers some media content
+                   license:bsd-3))))    ; horizons/ext/speaklater.py
 
 (define-public gnujump
   (package