Let Retro Points earned in a DKT attempt be kept, regardless of clear/fail

Minor suggestion, but currently in Demon King Tower, if you collect coins from chests but then die, you don't earn any of the coins you've collected and get nothing for your efforts. I think you should still earn the points accumulated for two reasons.

1. It makes your failed attempt feel less bad
Self-explanatory. While failed attempts will still sting, especially after many attempts, being able to earn at least a bit of retro points each time would make it feel like you're at least getting something out of it, aside from practice for the level.

2. It makes going for the coins more worthwhile
Because of how many attempts a floor section can take, the coins end up becoming really worthless I would argue, due to the fact that collecting them doesn't matter unless you're guaranteed to clear. In higher difficulty floors, I find myself and others to end up skipping collection of the coins (unless they happen to be with an HP refill) because why waste the time to collect them if you aren't 100% confident you will clear? Sure, the coins are usually on the main path, but you still have to stop and pick them up, when you could just be putting your effort into making sure you clear the floor section.