I’ve occasionally seen this game compared to Diablo, but I don’t see the resemblance. It’s far closer to a combination of Ys‘ combat style and Zelda‘s grass-slashing and key item collecting.
It’s certainly on the more difficult side of things as far as RPGs go and you’ll probably die quite often until you get the hang of ‘dodging’ enemy attacks. The limited number of active skills you can have is another issue and leveling up is a bit of a trap; you get 6 attribute points to distribute however you want each level, but if you don’t spend them 2 Str/1 Int/1 Ref/1 Con/1 Will there will be a ton of weapons and equipment you’ll be unable to wield by the end of the game. Having to often swap between key items (limited to 4 active at a time as well) is also annoying.
Length-wise it’s pretty short (my playthrough clocked in at a little over 9 hours), though it doesn’t feel short… the final dungeon in particular goes on for ages (and requires something like 40 keys)… and will definitely take longer if you avoid using any sort of walkthrough and/or have a bad sense of direction.
Overall I suppose it’s decent enough, although in the end it might be better to get invested in the Ys series instead if you haven’t already.