I think this was a pretty well done project! The use of telephone boxes as a combination checkpoint/shop was a pretty elegant way to approach the 'checkpoint' theme, and while calling xp 'cross points' just to set up the 'cross path' was a bit of a stretch, it was also too funny to not respect it.
The combat was simple but it got the job done; some more enemy variety early on would've been nice though. Maybe instead of just putting increasingly large numbers of the basic enemies near the end of the first level, there could've been one or two bottle throwers in those fights? The combat definitely got more engaging once they showed up, and same with the 'elite' guys.
Using time as a lives system was clever, and gave a good reason why you could get more of it throughout the game. I did notice that I didn't seem to actually be losing any when I died though? I died about once a level going through the game, but the end of level summary always credited me as losing 0 hours from deaths.
Overall this was a quick but cool game, and definitely see room for it to grow just by building up on what's already there.