meh
Looks nice and all but really didn't capture the awesome level designs you find in Nintendos sidescrolling Mario games. Theres always a way to beat the levels in these, but here I found myself stuck more than one time. There has always been a way to beat a level in old Mario games, but here I couldn't proceed because I couldn't break blocks(small), or because I couldn't jump high enough to escape a pit so I had to start over. And whats up with the Fireflowers everywhere? I'd rather see some 1-Ups instead of collecting 10 Fireflowers in each level.
Also you could just fire-spam through the levels. Many enemies running into your firespam don't replace fewer well-placed enemies.
Hope this critique helps you with future jump&runs!