Great game! I play with my 5 years old son a lot on the Switch. There are a few bugs that I hope you will improve in the co-op mode.
1. There are some major lags in the boss bottles for co-op. Slightly less when you solo, but the co-op gave 3-5 secs lag on Nintendo Switch.
2. During Co-op, when you enter/exit the chest room. Only one play can enter the room where is the other play is lacked out side the entrance. You need to move the first character to the entrance to "pick up/unlock" the second player so he/she can enter. This is extremely annoying.
Again, great game and please fix these bugs.