@cronix thanks. Good observation and interesting point.
The missing "hand" pointer is a side effect of BlockLike. The clickable icons are not image elements wrapped by anchor elements with href. Instead they are Sprites with a click listener attached in JavaScript via their whenClicked method.
My first reaction was to say "yep, let's change the cursor and help the students" and I was thinking I would modify BlockLike so that any clickable entity will have a pointer cursor. Then, after reading around the web [1][2][3] I realized that I shouldn't, as in most cases, the click on the Sprite is an action not a link. Those four icons on the homepage are the exception not the rule.
So, to come around a full circle, changing the mouse pointer to a hand is indeed the developer's responsibility. That being said, this project is both relatively complex and wide in scope with a lot of moving parts, thus it is bound to be rough around the edges. UX, like learning is a never ending job...
[1] https://medium.com/simple-human/buttons-shouldnt-have-a-hand...
[2] https://ux.stackexchange.com/questions/109739/should-anchors...
[3] https://ux.stackexchange.com/questions/36871/whether-to-use-...
On the website, you might want to add the mouse pointer back when hovering clickable icons. It's not immediately apparent that they are clickable since the cursor remains the regular arrow instead of changing to a pointer.