I've become a bit obsessed with Rogule (https://rogule.com/) by @chris. The only downside is that I can only play once per day.
Would be nice to have a “redemption run” option where upon losing get a second chance to beat the level, even if it didn't count towards the current streak or stats.
@erunyon thanks so much Erik - several people have asked for this so I think I need to implement it!