Nice game overall
-The gameplay is amazing. The map by itself would be nothing special; nor would the flying thing - but combining the two manes a great game. The gameplay reminds me of the old heli attack games, where a giant enemy constantly lurks overhead, no matter where you go. The background style also looked very good, although strangely familiar in a way. I think that's because of its similarity to the games where you have to guide a bubble through a cave.
-The big weapon at the end is also very nice. I didn't actually realise there were many different types of weapon you might end up with though, until after I'd completed the game several times - since the first time I played, I found something like 20 machine parts - then found all of them every round after that. Perhaps as a special feature for finding everything, you should be able to see all the weaker machines too, in a menu? The weapon you build at the end, after collecting every machine part is very cool, by the way!
-Controls often have a response time that is annoyingly slow. You press "jump", and it will take a very noticeable amount of time to actually do it, sometimes. This shouldn't be happening at all, considering that this isn't a particularly graphics-intensive game. That's really my only complaint and it could be on my end. So overall it's a pretty good game with lots of fun to be had playing it.