Hi, thank you so much for reaching out! Unfortunately, the asset pack is not set up for tiling software such as ones built in RPGMaker, etc... This tiles set is best used as parallax mapping asset.
In order to force the right perspective of some larger items, we had to break out of single tile sizes. Affinity Studio is free at the moment, and it will open our file and let you move things around without a problem. It is the best solution without having to redraw many of the assets available.
Looking forward to seeing what you make using our assets. Please feel free to leave a comment linking your game once done!