Awesome and unique game idea! I love it! Reminds me a bit of Mario Maker or the brilliant Ultimate Chicken Horse.
The movement and gun play feel pretty good. It's fun moving through levels. I think there is a lot of potential to turn this into a proper game with more Objects and Enemies and Challenges.
The UI was a bit tricky to understand. Some tooltips or explanations would have been nice but it was manageable to build and play levels.
The visuals are pleasing. I really like the player character and the snail. Destructable terrain is a nice touch and makes shooting even more interesting because it would totally no help you destroying the platform you're standing on :D
Cool game! Well done!