Wow, I cannot believe this is your first game, seriously, this is a fantastic first game.
The pixel art is great, combined with the lighting, it makes for a cool dungeon experience. Also, the dim lighting also adds to the gameplay as the holes are not immediately visible, forcing you to be cautious of where you step.
The music and sound effects are appropriate and are quite whimsical and comedic, accentuating the humorous situation of using holes to defeat enemies.
Only complaint is that the checkpoint system is a little too brutal, as dying will set you back quite a ways back.
Considering you made all of this in 7 days for your first game, this is some crazy amount of talent. All in all, fantastic work, I will be lying if I said I am not a little jealous of your talent, hahaha.