Nice track!
You mentioned not being sure if you handled the 'climax' part well and I have a few tips for you. I think part of the issue is due to over using reverb and reusing the same melody a little too often before the climax without variation.
For the reverb, often, less is more. Learn to mix clearly and precisely (try mixing in mono, it really helps) and you'll need less reverb. This means that when you DO use reverb (like the vocal synth in the end) it will really wash over the track and create depth and drama.
For the melody, since there are no modulations or changes, it doesn't stand out. What you could have done is had a few notes change in there somewhere and maybe changed the rhythm up. The 2nd note is always the longest. What if you made the 1st super long, so long as to add a beat before the 2nd note but cut out the last beat from each bar, even from time to time or in the first one?
Hope this was helpful. I really like the chiptune sounds in this, they blend well with the rest.