The dedication to the arcade aesthetic is commendable! The whole vibe is right at home with Mappy, Mario Bros, Burger Time, etc etc. I'm impressed with the detail and character you we're able to achieve with such low resolution! The gameplay itself is simple, but has that addicting quality, just like the classics.
Criticism:
I was disappointed to see that the level plays out the exact same every time. I think there's some simple things you could do to mix it up. It would also be cool to see things progress in difficulty the more levels you complete. Moreover, having a different scene to look at would be great. I don't have much incentive to play to the high score point as it is.
The Spray has no indicator for it wearing off, this definitely got me killed a couple times. Now, this is certainly true of another classic, "Donkey Kong", but that doesn't make it a good thing. I would take a queue from SMB1 here, and just give the player a second or two longer after the music has stopped.
The screen real-estate. The art is adorable, but It can get a little squinty trying to look at the game. We're already dealing with a vertically oriented game, and I can't even use the whole vertical space of my monitor.
Nit-picks/Small things
- You can't go down the stairs once you've started going up
- The keyboard doesn't work at all while a controller's plugged in
Overall, all the ingredients are here for a great simple game! I hope you take some time to tune things up :) Have a good one!