We are staying in the area for several weeks to visit family, and decided to stay at this hotel for one night entirely for our kids to use the swimming pool(s). The property description on Expedia says there are various pools AND a water park for an extra fee. This is not true. There is only the water park that you have to pay extra for. Also, you must exit the hotel and then enter the water park in a separate door way. Half of the water park was closed for some reason (including the large water slides). The areas that were open were pretty dingy and worn out looking (grimy water stains on walls and poor interior lighting). Also, they require you to wear a cap if you want to swim, and many of the lifeguards spent their time staring at their smart phones.
On a positive note, the rooms are well kept, clean, and mostly updated. Additionally, the restaurant on the 13th floor had wonderful views of the river. However, we did see mold growing on the grapes set out for the breakfast buffet.
Yeoju is definitely worth visiting, but if you require a high standard of lodging, maybe this place should not be the first choice. If you only need a room (i.e., no food or swimming), it could be pretty good.