I just tested the latest flatpak of Games (see below) and got a crasher immediately after the games started to show up.

My games library is basically a whole lot of NES games and nothing else, it's located at ~/Games and that directory is scanned by tracker.

====================================================

mattiasb@localhost ~ $ flatpak update org.gnome.Games
Updating application org.gnome.Games master

1 metadata, 0 content objects fetched; 313 B transferred in 3 seconds                                                                                                                                  
Updating related: org.gnome.Games.Locale

1 metadata, 0 content objects fetched; 313 B transferred in 1 seconds                                                                                                                                  
mattiasb@localhost ~ $ flatpak run org.gnome.Games 

(gnome-games:2): Gtk-WARNING **: Locale not supported by C library.
	Using the fallback 'C' locale.
Gtk-Message: Failed to load module "pk-gtk-module"
Gtk-Message: Failed to load module "pk-gtk-module"

(gnome-games:2): Gtk-WARNING **: Failed to get the GNOME session proxy: The name org.gnome.SessionManager is not owned

(gnome-games:2): Gtk-WARNING **: Failed to get the Xfce session proxy: The name org.xfce.SessionManager is not owned

(gnome-games:2): Gtk-WARNING **: Failed to get an inhibit portal proxy: The name org.freedesktop.portal.Desktop is not owned

(gnome-games:2): Tracker-WARNING **: tracker-backend.vala:211: Falling back to bus backend, the direct backend failed to initialize: Locale mismatch, cannot use direct connection
**
ERROR:grl-net-wc.c:730:get_url_cb: assertion failed: (c == d)