Quality tech; dithering and such, I don't know what the challenge is but I'm guessing you didn't inflict that palette on yourself by choice

. Anyhow, less flat:
- Try cutting back on the background blue on your fruit; makes it blend in. Ramp up that underused grey instead: you need to fully leverage all the values you have.
- Why has everything got a rimlight? plot from the lightsource to the object and light that stuff up.
- Similarly, highlight position is not at the closest point to the lightsource: angle of incidence = angle of reflection; you can google examples.
- Maybe light up the floor a bit in line with everything else
- Candles tend to light up internally rather than casting a strong shadow on themselves.
- I wouldn't put put a highlight on the 'nana; they're kinda matte.

Also, holy balls lot of activity here.