I have a some design concepts that I think would really make this game a lot more fun and challenging to complete with a 100% collection rate.
Here's a list of a few that I've really been thinking about!
*Per-World Completion Rankings
Basically what this will do is it will show you where you're missing collectables (Which by the way can range from simply jewels you missed to actual upgrades, as they all count equally)
You must have 100% life to pass. Placed at the end of difficult platforming sections and house potent but optional equipment.
Save points are actually a pillar in the game that you press down when you're near it and it saves your progress. If you die, you return to the last save point you visited.
With a certain item, you can float up these slowly to reach different areas.
When you kill a creature, it is only dead until you leave the room. If you come back, the enemy will also be back.
And finally, here's the list of currently planned collectables/equipment:
Feel free to interpret their use at your own will and share what you think each will be used for! :P
*40 Golden Scarabs
*32 Archon Hearts
*10 Soul Salves
*3 Barbed Arrows
*3 Winged Charms
*1 Platinum Circlet
*1 Tin Ring
*1 Fire Essence
*1 Ice Essence
*1 Peridot Pendant
*1 Maple Sapling
*Other 50% of completion is Jewels