I find myself addicted to this little game even I hate most open world games.
The game has ridiculous amount of depth for such a small game. Totally hardcore Jrpg formula.
I bet the dev must from japan or who is a fan of hardcore Jrpg games like demon souls.
The saddist game setting in the adventure mode will torture you to the last living breath of ur char.

but it's getting addicting.
The game remind me a lot of demon souls and spelunker HD. Encourage player to learn and figure out stuff on their own.
You can tell the designer put a lot of effort into tweaking the mechanics to ensure a good torture experience. Every smart designs.
A few suggestion
1:put some words above/below each component picture to explain what they are, so player can intensionally search them out during exploring.
2:The sandbox mode could use some hint to illustrating more on point of interest which will help exploring. I found myself often miss key point of interest just 1 feet away from my revealed walk path.
3: let user set customized landmark on map.
4: warm hole teleports could use some color coding to distinguish which connect to which.
That's it for now. Might do a full review of it if I get time, just too busy with this site's coding and design. Sigh...
Overall, Cool game, highly recommended if you are a hardcore Jrpg fan who like to learn game mechanics by numerous death
