Thanks for playing!
There’s a win streak counter, but it’s on the “New Game” screen: it shows up below the “player vs cpu” icon (the game only counts the win streak for vs cpu matches). It only shows up if the streak is larger than 0, though.
You can also see your “progress” towards the achievements on the achievements screen. They show up besides the checkbox (for the achievements that require a win-streak)
Regarding the pvp achievements, I had them during development but eventually removed them as it was way too easy to just cheese them (just play against yourself and lose lol). Nonetheless, it would be cool to keep track of win-streaks for each “side” of pvp matches.
BTW: did you figure out the secret achievement? :P