The art and sound is very solid. The gameplay too, feels relatively polished. I think this might come out as one of the better games of the jam. The seamless time period switching looked *really* good, and was a worthy inclusion even despite not being tied to any mecanics.
I think your game was kinda lacking in some aspects - The character felt floaty, and the game was trivially easy. I dont think i got hit once on the boss, and spent most of the fight standing still. The level design needs more work too - i remember vididly one bit where i was just jumping up a long vertical shaft, hoping it would end soon. That took way too long.
VERY good jam entry though. well done.