Its already on itch! Get it now at $24.99 before the price increase to $29.99 on the 6th
Steam will be when the game is officially released. No word on that beyond "Q2 2017".
Hopefully that means 'calendar year 2017'. The company I work fro now our 'fiscal year' starts in July so "Q2 2017" is actually December which is.... ultra confusing to everyone :P