As of recent, UTG Software have made the HD version of Suwapyon 2012 free for download.
Download link here. (for the record, it is the full game)
Replays done on the non-HD version of Suwapyon 2012 should work fine with the HD version. (at least from my testing)
If the game runs at 30 FPS with the default options, try setting the "フレーム更新の処理" option to either "VBlank検出" or "タイマー" (at least these two make the game run at 60 FPS for me). If the game slows down, try disabling Aero in the game's options (デスクトップコンポジション無効) (will have no effect on Windows 8, since you can't disable it there).
Important note: The HD version uses DirectX 11, meaning you
must be on Windows 7 or later. It will most definitely not work on Windows XP, and very likely not on Vista either (despite what the manual may imply).