Unfortunately its a known issue, the same happens in many other ported games in this franchise, and since this has not been repaired until now i am pretty sure they are never going to fix it, if you still can ask for a refund.

There's an issue with GPU utilization like in other recent Gust games, your GPU downclocks in some situations and the game lags.

If you have an Nvidia GPU, the problem can be fixed by doing the following:
- Right-click on desktop, choose Nvidia Control Panel
- 3D Settings > Manage 3D Settings > Program Settings > Add > Atelier Lulua
- Set "Power management mode" to "Adaptive" and save the changes.

Note that you can also set it to "Prefer maximum performance" but your GPU will be running hotter.

Originally posted by iriyap:

There's an issue with GPU utilization like in other recent Gust games, your GPU downclocks in some situations and the game lags.

If you have an Nvidia GPU, the problem can be fixed by doing the following:
- Right-click on desktop, choose Nvidia Control Panel
- 3D Settings > Manage 3D Settings > Program Settings > Add > Atelier Lulua
- Set "Power management mode" to "Adaptive" and save the changes.

Note that you can also set it to "Prefer maximum performance" but your GPU will be running hotter.

It's work!!!!
Thank you very much!
Still got a little lag but better than before X )