So I have this in mind: It will be interesting if there’s a challenge which is time limited (maybe around 15 minutes or higher or lower) to score as much as possible. After the time is up, every enemies disappears (like how keys, foods, and gifts disappeared after a limited of time when you complete the mission) and confirm the mission is completed.
If you survive through the time limit, there will be a bonus (maybe 10% or 20% bonus to your score)
To make it extra spicy: You only have 5 limited slots, to make you choose your items more carefully. And this challenge should be a 1-attempt challenge like daily challenge