It's still a work in progress, but we now have a playable DOS port!

The SMS screen resolution is small (only 256x192) therefore the large border... But it does not get in the way of fun! (we will try adding some kind of scaled mode, but there will probably be visible artifacts)

Rendering PSG sound (3 channels + noise, with controllable amplitude) over the PC speaker (1 channel, on/off only) is.... interesting. We're not doing anything fancy such as PWM. Just switching between channels based on volume and pitch.. The resulting sound is not half as bad as we expected, but an option to disable music will still be added :-) Of course the final build will support OPL2 cards (AdLib & compatibles) which should be more pleasant...

Despite being a simple SMS game, the PC hardware requirements are quite high since everything (tilemap and sprites) is done in software, and a VGA card is needed for displaying 32 SMS colors. We use Mode X (320x240@60Hz) to get square pixels and a 60Hz refresh rate - the correct speed for the game.

We're not sure yet what will be the minimum hardware requirements, but at least it runs smoothly on this Pentium 133: