that's really great... and very ambitious!
not to complicate things but design-wise having only 1 lane, it makes it very linear making it not very competitive or exciting (I'm talking game mechanics). For example, I played a lot of HOTS and they have Brawl Mode that has a ARAM mode like this.. but the only thing that makes it exciting is the different heroes people pick since it's 5v5. 1v1 is extremely limited on a 1 lane map. I guess I'm talking about making it more strategic, add 1 or 2 more lanes.
I would also add some flair to the abilities, more pronounced sounds.. more drama etc..
but overall amazing effort! I hope you keep it going!