What a fantastic gem of a game. It's a very strong entry point to one of the greatest H-game series on the market.
The plot is coherent and easy to follow while still remaining interesting enough to keep you wanting to find out what happens next. The worldbuilding is well done too, with various locations giving you tidbits about the history of the world and how it affects the plot.
The gameplay loop is simple but rewarding. There are three main stats: Fame, Charm, and Lust. By raising these stats you'll gain access to better gear, quests, and H-scenes. The game admitedly has a slow start but it does ramp up over time. I prefer this kind of slow progression because it makes sense from a story perspective and the resulting pay off when getting to a new scene is much more rewarding.
Iria is an amazing protagonist. She's cute and sexy at the same time, while her cheerful yet somewhat naive attitude makes you want to support and lewd her. That doesn't mean she's dumb, just that she's inexperienced. So she won't be selling her body the moment she steps foot in town, which is great. This makes for a system where her corruption is gradual and way more enjoyable.
There's a decent amount of H-scenes and with a matching variety too. The top tier art and context behind the scenes all combine for a wonderful experience. Every H-scene occurs in the city, so that means no game over scenes or battle fucks. It's intentional and lets the focus be on Iria's interactions with the various citizens of Trielebe. Some scenes are infinitely repeatable while unfortunately, some do have an ending and can only be replayed in the recollection room. Personally, I feel like there was some missed potential in what could've been offered. For example, an outdoors scene, public sex at night, getting messed with while sleeping at the park, nothing at all with the maid outfit, perhaps an optional x-ray toggle, etc. There definitely should've been unique dialogue about deflowering Iria. I also didn't care much for the hypnosis series of events.
The game is a bit dated and in shows in some quality of life issues. There's no in game options menu so you can't adjust the volume to a specific setting, it's either completely on or off. You can't load a previous save from within the game, you have to go back to the main menu then pick a save. There also isn't a costume change mechanic by virtue of the setting.
Overall, Gran Ende I has a ton of things going for it and very little holding it back. Gameplay's great, art's wonderful, scenes are very erotic, you can't go wrong with playing this. It's honestly bewildering how this hasn't been officially translated already. The dev has only improved by leaps and bounds since then so go check out the sequels if you enjoyed this game.