One of the keys of getting a convincing digital image is correct lighting. This can be very tricky especially for realtime content where a lot of the computationally heavy lighting calculations need to be avoided by using work arounds. This means that it requires a fair bit of technical knowhow in order to get an image that both looks good and runs well on the target hardware. Luckily at Studio Delta we have tons of experience working with realtime content to be able to get projects to look good even on lower-end systems.
As you can see from the above screenshot from Unreal Engine, the lighting can easily be adjusted to give completely different moods
Here you can also see a different environment with variations in mood and composition. The sky is truly the limit with this technology.