Just so you know, you can scale the game even without a mouse simply hold Ctrl and press + or - to zoom in or out. In some browsers, like Firefox, you can also go to the three-line burger menu at the top → Zoom → +/-.
Regarding the invisible wall: this is a known bug that unfortunately couldn’t be fixed in the InTime version. As mentioned in the description, it can be bypassed by moving over the train tracks.