Ask HN: I want to make a boring process fun. Fast-loading HTML5/JS/CSS3 games?

This may already exist, so I figured HN would be the best place to ask.

I am working on a large inventory system and throughout there are a few number crunching functions that take time to execute. I would like to add a small "please wait" game that will take the edge off of an incredibly tedious and painstaking task.

Users are very happy with the system on the whole, but I feel like I can make the annoying bits something to look forward to. I like the thought of them saying "yes, this sucks, but at least there is something to look forward to".

I have no interest in game development, but I also don't want the bloat of a committed game engine, etc.

Any ideas? :D

EDIT/HN devs: When I first added this post, it included <p> tags instead of CR. After editing and removing, it appears it doesn't happen again.

EDIT 2: I would pay for a service that provided interstitial games.