Alright, here's a simple example of a Roblox-based game featuring a waterpark and hotel. The game utilizes JavaScript and is enclosed within script tags within a single HTML file. Please note that this example is just for demonstration purposes and doesn't provide the complete functionality of an actual game. You can further enhance and modify it according to your requirements.
In this example, we've created a game container (`game-container`) that holds two elements: a hotel (`hotel`) and a waterpark (`waterpark`). The hotel is represented by a red rectangle, and the waterpark is a blue square.
When you click on the hotel, it will display a welcoming message using an `alert` box. Similarly, when you click on the waterpark, it will show a message indicating the excitement of the waterpark.
Please note that this is a very basic demonstration and you can add more functionality, graphics, and game mechanics to make it a more immersive Roblox-based game.