Oh that's a kind of puzzle I haven't seen before. It was hard to get the hang of the rules.
Also, I like the illustrations but they get too much in the way of the gameplay. The WALL and the opened tiles don't contrast enough with eachother, in other words it's hard to tell them apart from a glance.
I've featured this game in my showcase, though at the time of editing I didn't read the comments below so I didn't know what Nurikabe is. So you can ignore my question in aforementioned video:
https://youtu.be/PoWrHcmGjbU?t=3404