Hard Hat: an exercise in game design (part 2)

So, continuing with our experiment to see if the mediocre arcade game Hard Hat can be improved, we must first start by recreating the game.

Instead of recreating the arcade game exactly, I'm going to approach this experiment as though I were doing a port of Hard Hat for either the Colecovision, Sg-1000, MSX, or Ti-99/4a  home computer.  More precisely, I'm going to convert the graphics so that they are compatible with the TMS9918a video chip.

Here are some color bars from a TMS9918a video chip

I'm very familiar with the TMS9918a video chip's specifications, and it was a pretty common video chip in 1982, so if Hard Hat was going to be ported to a console or home computer in the early 80's, the port would have likely used this video chip.

The TMS9918a  produces a display of 256x192 pixels and uses a 16 color pallette.  This chip can display 4 16x16 single color sprites per row, and can display 2 colors per 8x8 background tile.  Special display modes can display more colors per background tile, but are still limited to 2 colors for every 8 horizontal pixels.

This chip is similar to the hardware of the arcade game, but not exactly the same.  So, when converting Hard Hat to the TMS9918a's specifications, a few changes need to be made.
The biggest change is the game's vertical resolution.  The arcade game has a higher vertical resolution than our target specs, so to make everything fit on-screen, we will need to remove one of the rows from the playfield.
This change affects the accuracy of the port a little, but doesn't really impact gameplay.  Though, one benefit of this change is that the word in the center of the screen is now more centered.

The sprites will all need to be single colored.  The player and the tornado are already a single color, but the hammers and the letters will need to have their colors reduced.
A few background tiles need to be redrawn a bit, but overall, the look of the arcade game can be reproduced with a good deal of accuracy.

Arcade original (left) and TMS9918a version (right)

As a self-professed pixel wizard I always feel the need to improve things a bit, so why just stop at converting the arcade graphics, why not take it a step further?  The arcade hardware can only produce 8 very basic colors, so let's take advantage of the TMS9918a's 16 color palette and pretty it up a bit.

The game has a construction theme, so let's make the walls into wooden boards, give the scaffolding a more natural grey, and make the connecting pieces look more like scaffolding connectors.

For the sprites, the player can be re-drawn to look a bit more like an actual hardhat with legs, and the animations can be improved a bit too.
The arcade tornado uses way more frames than necesary, so it can be redrawn to use fewer frames and look a little nicer.

So, now with the graphics converted and improved, we can move on to the next step of our experiment: programming the Hard Hat port.

To be continued...