The fact you made this in Scratch of all things is really impressive, and you've combined some complex behaviours in the engine. Looking at your previous games, you've made a significant leap which is awesome to see. There's some shooter mechanics, well executed item combination and the sacrifice tying the experience together. I like the symbol illustrating the strange and occult nature of the player's activities.
For constructive feedback, I'd say the game uses diagrams to signal what they're meant to be doing, but sometimes the game behaviours (i.e. the knife or match not doing what I expected it to) may lead them to confusion. Finding ways to anticipate how a player might approach something differently can be helpful.