This is great for your first game. The movement felt very satisfying and the big doors and plant pots make me feel like a little guy so I think you accidentally hit the theme anyway haha.
There are a few easy/cheap ways you could add some extra polish and game feel to your next one. Normal maps on those big high quality textures would make them look less flat and some SFX variation (randomly change the pitch/volume within a range for repetitive sfx like your jump noise). On the topic of SFX there is some quite noticeable clipping from spamming jump and the sound cutting into the previous one, take a look at sound pools and polyphony in godot to deal with this.
Look forward to seeing your next game, keep creating!