Underbed Lego Storage

We were in desperate need of a lego storage solution for our son's small bedroom. I made this for his 7th birthday. I saw a photo of a similar one as a result of a google or pinterest search and decided to draw up some plans.
I recessed the top slightly so that pieces won't fall off. I just glued thin cleats to the inside of the box to hold the lid, (using spacers to get it at the height I wanted) Ideally the top would be reversible however I didn't quite get one of the dividers square so it only fits one way. I used Posca water-based markers to do the text. Make sure you wait until the text is really dry before you try to seal it (don't ask me how I know that...) Turns out that the markers don't react well with the brush on poly so I just left the text unsealed.
I was just going to have one handle on the front but then I made a stupid mistake and wrote the text so it would be upside down when pulled out (I know, dumb right!) So I added another handle on the other side. I used a water-based enamel for the whole box. Not sure if that was worth it of if I should have just used flat and given it a top coat of poly. I used a brush on the inside corners and found it really hard to get an even finish because I rolled the flat surfaces. Painting the pieces before assembly would probably fix this.
Added some castors so it can be pushed under the bed.