I thought new game plus would be exciting, some ideas are
- Allow items to be carried forward
- Even Harder / more enemy bot
- Extra hard boss?
- new sandbox game mode: Boss rush? infinite challenge?
- 1 ultimate weapon?
- 1 hidden new exo (maybe added in expansion)
Perhaps just saying that the robot side has their center commanding backup circuit mastermind accidentally reboot
or some simple excuse with one or 2 short short nice screenshot / voice overs to begin the whole thing again.