Thank you for your feedback and "Isles of Sea and Sky" looks pretty cool I'll check that out.
Your suggestions are really cool, I did have plans for making puzzle rooms that would give the player new abilities, but didn't have time, but the idea of having a past self clone is pretty neat, I only came up with an ability that rewinds all enemies around the player.
As for the boss suggestions is really creative and would have been a lot better than the boss i had planned. My original idea with the boss was to make it so that it would know that you looped back and would have a big attack ready when you used ability.
But due to time constraints I didn't have time to complete my ideas.