Not terrible for first attempt, but here is my critique,
For starters, everything looks out of resolution, how ever you got your sprites they are not a source to be used again, it makes everything look blurry and make added in objects look out of place.
Secondly, if you have a mic, you can voice act. At least enough to make something like this, I can understand wanting more voice actors but you must not give up without trying.
Lastly, I will input my nit-picks:
Ash/Jeff's mouth is too high, it looks like his forehead is dancing. Things like text that you added in look out of place and incorrect. Green rock. The intro and outro are a bit too long, for pacing reasons I suggest you edit this.
That's all of them. I hope you read this and respond if you do not agree with some of my reasonings and hope to clear them up. Good Luck.