Solid game. reminds me off the old Mario classics ^^! But is indeed very hard. haven't made it to the end .
Part of the reason for that is that once you die, you basically start over. Redoing the same parts of the level over and over again is not a lot of gun, especially with that fairly slow movement speed
The art-style is very simplistic but for some reason i really enjoyed it. (the grass texture cold be more creative than a flat green though :P)
Aside from that, i really enjoyed it. Well done!