I wasn't aware of Hexcells, but it looks a lot like Hexceed (which I was utterly consumed with until I finished all the levels and all the DLC). If you like Hexcells, you'll probably like Hexceed too. It also free and has hundreds of levels. You only pay for the DLC, all of which is very reasonably priced.
Disclaimer, I'm just a fan! Not connected with Hexceed in any other way.
Edit: Just went back and completed your game. Perfect difficulty level! Shame it doesn't save your progress though. Still, one of the best games I've seen in the jam so far.