I was able to soft lock and not advance past the relic rewards page.
desktop version 0.5.6
steps to reproduce:
1. have every legendary relic obtainable via level rewards; counting lens, phoenix feather, pure blessing. (I didn't have GGEZ)
2. have legendary scroll to force legendary rewards
3. beat a boss level to get relic rewards
4. skip stage rewards button is not visible nor clickable
since none of the legendary relics stack, there were no candidates and thus bugged.
I did it by getting legendary scroll as a reward and then re-rolled into the above screen. re-rolling again refreshes the same problem.
note: by reloading the game it cancels the reward screen and spat me out into world 5, so not an absolute soft lock.