The trial version can only play the first level. To unlock other levels, you can only play the official version. You can buy the official version in the description. If you buy it on dliste, there is a discount code. There is also a discount event now, which can save a lot of money.
You can get the discount code below：
https://ci-en.dlsite.com/creator/14005/article/1477871
then you can use the discount on :
https://www.dlsite.com/maniax/work/=/product_id/RJ01413098.html