It does feel a bit bland. The colours are all a bit dull and have a blue cast, except for the dirt, which draws attention to itself precisely because it stands out more than even the actual walkable grass does. Consider adding some warmth (yellow) to the greens so that they stand out better from the blue background, and using a less saturated colour for the dirt, so that it doesn't jump out so much.
The jumping lacks impact and looks floaty. Consider having the character jump and fall faster, but with "gravity" slowing them down faster as well. That should make the jumping feel more natural and "punchy".
Similarly, the recoil feels very weak and slow for a game with "recoil" in its title. Consider making the initial acceleration from the recoil higher, but again, fade it off quicker to compensate.
The enemies all feel rather bland. I like the cartoony look of them and I love their death faces, but they don't seem to have any sort of theming, and the death faces all being largely the same feels like a missed opportunity to give them (and the game) more personality.
On the subject of personality, the environment feels very scattered, like you're not sure what you're going for with it. It doesn't seem to tell any sort of story or establish a mood, and it has both realistic parts (the palms, the dullish green colours of the palms and grass) and abstract parts (the smiling... hills?, the stylised grass and dirt, the sky...). If you're not using the environment to help tell the story, maybe focusing more on the abstract parts and making everything more cartoony would help.
