Really fun concept! The gameplay was a little clunky, likely due to the time constraints you were under, but it was really fun trying to see how much further you could get with each gameplay session.
We felt that it didn't totally land the "loot" theme, as you were really only collecting one item (keys) during gameplay and they only served as a barrier to entry to the next part of the level. We were looking more for items that you could earn/unlock through gameplay that would in some way affect the gameplay (making you stronger, giving you new abilities, allowing you to change your appearance, etc). It seemed like maybe that was what you were going for with the different types of light that you could choose at the beginning of the game, but they only marginally affected gameplay and were available from the start of the game so there was no "unlocking mechanism" like we described in the announcement of the theme.
If you were to flesh out this game further, we'd love to see you dig into the loot side of it. Maybe make only one light source available from the start, with others becoming unlocked as you perform certain tasks or get further into the game, and having different affects on the gameplay like making it easier to find certain types of keys or giving you more time to search but making the keys smaller/harder to find.
Great work, and keep it up! We can't wait to see what you make next.