Yeah, I agree with the controls sentiment thing people are having. It could use some work in being polished. If you want an extra hand in helping with graphics, I can lend a hand if you like. By the way, loved the tomato rolling when you gain in speed. That's super adorable! Do you think the controls would benefit from having a more sudden deacceleration when turning, especially at full max speed? Would certainly aid in giving tight controls, I think.
You may want to limit the player's jump height. I understand that the game is...supposed to have a parkour feel? Walljumping and stuff, I mean, fluid fast movement (like Super Meat Boy), but that huge jump height is rife for abuse. It's also because it can become difficult to gauge where you will land with such a high jump.
I think the Escape key should just restart the current level, and you should add a pause function if you haven't planned on doing so yet.
The game should be a bit clearer in where to go with the tall rocky outcrop in the second level. I got confused really easily and tried to futilely jumpclimb the rock wall, since there was no easily noticeable indicator of where to go for me, since it wasn't really clear that palm tree had a solid canopy. The switches also have a really weird and annoying small hitbox. Even if it's intentional for the tomato to be small in terms of weight, that's a tedious feature to play with and would be more prone to causing player frustration. Remember: When building and balancing game mechanics, think of anti-player frustration. Doesn't mean you can't make the game hard, but know a difference between hard, fair, and balanced and unbalanced and rage-inducing.
Checkpoints would be super useful, especially third level onward. I found an oversight, maybe...you should make it so the goal message appears if the player passes over and above, such as with the third level. Also, the hud on the left is a tad distracting, like I felt like it could end up obscuring level geometry (especially if you end up with a tricky jump puzzle), and you should just shrink it/clump the info closer together.
I have to commend you for the atmosphere of the fourth level. Going deep into the water for the first time, my first thought was 'woah, this is really creepy stuff'. If that's the intention that you wanted to go for, bravo! Also, on a more negative note, the unclear direction note I made about level two is much more clear in the underwater level...I could barely tell where to go besides down, and it took me a good while to figure out where to head towards the goal.
It may just be me, but I kind of dislike the vanishing platforms in level 5. Also, the mushrooms/flowers feel super out of place to me. Maybe have gusts of icy wind to propel the player instead? I really liked that it was a vertical climb level though, reminds me of the Ice Climbers. Also, I found that it may be a bug...in said level, to the right of the double rows of sawblades, it's really easy to get stuck and not be able to climb back up. That mushroom next to the spike walls feels really unfair. The section with the three bugs together, I couldn't get past that as of this writing. Tried four times, got increasingly frustrated with each death.
Levels four and five could have easily been my favorites, but due to inherent level issues I described, they are not. Level three, probably, because it reminds me of S&K's Mushroom Hill Zone, but it seems kind of bland...like a hilly area with a serious vegetation overgrowth issue and an outbreak of shrooms. The nostalgia kind of wore off for me, so that particular level could maybe use some asset improvement?
I think a scoring system more complex than points could add a nice skill ceiling. I.e, grading the player with a letter grade, based on time, potatoes collected, damage taken, etc.