Oh god! OK, I'll be extremely bias when we come to talk about your game, you know why?! because...I loved it! My guy, I had fun! but like truly fun! The fast pace made it really challenging at first, not impossible but just about hard enough (which is a positive!). The only 2 things I can point out that you could've improve with it were indicators.
To explain how the experience was, I'll say I clicked download and opened the game, I didn't read anything (which I know, sorry but it's what people do right? haha) which made me when I started the game a bit confused, I saw the planks to build the bridge as nothing more than what the batteries and potion were, things to be avoided rather than to be build with. firstly I just though "Oh okay, this is fun I just gotta survive for a long time and get a score right?" but once I lost after I while I was like "right?!" which took me to..you know..check the page to figure out what to do? ;V which yes the picture you put right bellow the main screenshot made me instantly understand how to build the bridge but once I was in the game it was quite "unclear" so maybe indicate to the player the use of the planks with an indicator of some sort?
Quick add-on just to be picky was the way the level select worked, why not just open the level when selected? I mean, I felt a bit weird when I selected the level and nothing appeared to have happened. It took me a second to figure out of course but it was certainly a confused second ;V.
Overall, there is no way I can say it was a bad game, it was fun and challenging! Nice one man! I know I seemed a bit mean, but honestly I was just trying to pick the red on the sea to figure something to help you out hehe.