This game is a fairly straightforward HRPG. You trigger events, fight, watch H scenes, rinse and repeat. Nothing is wrong with this formula, but Elena Quest doesn't do anything unique with it to make things interesting. The worst part about how this game executes on the concept however is how cryptic event triggering can get.
To start with you have to unlock the ability to fight on the field, and with some curiosity it's easy enough to stumble into the event but I've seen more than enough complaints that they've wandered for days without knowing how to progress, and unlocking combat is vital to progression. I don't think the game should necessarily be handholding the player but some sign-posting for crucial events like this would go a long way to alleviating frustration. Besides this you have instances of specific H scenarios that require you to be at specific places and times, all without any indication that a scene could even take place to begin with.
The worst part of the game for me however is combat. Combat is just a bust, with Elena's reluctance to even fight foreshadowing how hilariously underpowered she is. Enemies will mercilessly stun lock you for multiple rounds and level ups do very little to improve your offenses, so the only real way to get stronger is obtaining element spells. To unlock these you either need to farm drops from elemental enemies (at least these guys are among the easier ones to fight) or challenge the spirit to get super-powered versions of these spells. I got some lucky crits on the ice guy and the initial power spike helped level the difficulty curve a bit, but exploration and combat are so disinteresting and will be taking up the majority of gameplay to begin with.
After the gameplay loop settles in then the game stops really being difficult, but it's still heavily flawed. If you've gone through the initial loop and felt engaged enough to try unlocking the H scenes, then this game will keep you satisfied. However if at some point you start to wonder, "is it worth my time to unlock these CGs?" then my answer is no. H scenes are your standard still image fair and honestly I don't think they're erotic enough to be worth the time put into this game.