You will totaly need arrays for that!
Also the inventory you want to have is not the easiest with the different pages and all that stuff.
You could use a 3D Array or multiply 2D Arrays for that.
(or maybe put all pages in one 2D array but thats kinda chaotic)
Also a logic for sorting items and equiping.
However i think there are some pretty good inventory templates in the scirra shop.
If you cant make your own just use on of those.
If you like to try by yourself start with "binding" every slot in your inventory to an arrayslot.
So you will be able to load the content of the slot depending on the array.
So the itemslot ist just a graphical representation of the arrayslot.
I tried the game. I like it but i got a bug where i gave the right answer and he just dident attack.
Also is it possible to lose in this game? Is there a time limit?