You have picked an idea. The idea ticks all the right boxes. It's novel enough with just the right amount of familiarity. Now comes the execution part. Without proper execution, however good an idea is, it ultimately ends up in the trash can. What's enough for a prototype? 5 levels? 10? There's no right answer really. It all depends on the game.

I have played prototypes with 3 levels repeatedly for 15 minutes and I have also played prototypes where I took an exit after the first level. So, is the 'How many levels should I put there?' question really the question to ask? For some games, it makes sense to ask that kind of question. Games where content is king and not the gameplay and some puzzle games where repeated play gets boring very soon.

But the most important thing in the prototype is the execution of the core gameplay. If the core gameplay is good, players will play through all of the levels and then repeat until their thirst for play is finished. We'll explore 3 points today, which will help us nail down the core

1. Fun

Let's start with the most important thing, FUN! During execution, we have a very short time to get things done. We will try to do repeated builds and actually play it on the device. From the first build of the concept, we will try to understand which parts are fun. Our aim is to follow the fun. More about it here in a great video by GMTK.  

Sharing the build with coworkers and family is always a good idea. Let them play and ask them which parts did they feel were fun, and which parts weren't. Then you will have your work cut out for you. Maximize the fun in the fun parts and find ways to make the not-so-fun part more fun.

2. Toy

We have all played with toys

We have all played games

Let's carefully check the two phrases above. What's the difference? A game is something we play. But a toy is something we play with. What it essentially means is that a game has a goal and we play the game to reach that goal, whereas a toy is a playful object and it does not require us to reach any goal. Its only goal is to be played with. Sometimes while playing with a toy we make our own goals in our playground. Like, as trying to push a car to go through a gap and so on.

For our prototypes, we will try to make our core gameplay to be fun to play with. During development, the first thing we do is, make the core gameplay and then develop the goals.  After making the core gameplay, without coding in the goal, we will play to see if the core is fun to play with. If it's a character, then we'll make sure the character is fun to move around and play around with. Because if the game is fun to play with, the players will play the game irrespective of the goal or the number of levels, which is perfect for our prototype.

3. Story

Find a theme, a small story that the game tells. The theme and the game mechanics should work together. The theme should not feel like it's been forced upon the mechanics. It should feel one with the mechanics of the game.  

This is important for UA videos. We want our potential users to understand the core gameplay in a few seconds. When we have a small story that works with the core gameplay, every part of the game helps the user understand it.

This is a game about ragdoll flipping. Ragdolls are always a fun element to have in a game. And mixing it with flip mechanics makes it more fun to play around with.  In the reference above, we have a small story that the game. As ninjas are always jumping and flipping around, it makes sense to have a ninja. We also see the ninja doing a flip to avoid a flying star.

The mechanics and the story are working together. The mechanics are saying that you can do cool flips. And the story is reinforcing that by showing a ninja who does flips and also shows a short term goal of avoiding the flying star

These points help a lot in nailing down the core aspects to cover in the very short time frame of a hypercasual game prototype.