Bike routes are a very new thing in the eastern part of Croatia but I managed to find a few that are feautured on the Danube bike routes (and if you bike you'll probably get quite a few people staring with open curiosity as some of the villages have not had many tourists, especially not on bikes) :
Section 1 : Udvar - Duboševica - Topolje - Gajić - Draž - Batina - Zmajevac - Suza - Kneževi vinogradi (34km)
Section 2 : Kneževi vinogradi - Grabovac - Lug - Bilje (19km)
Section 3 : Bilje - Osijek - Nemetin - Sarvaš - Bijelo Brdo - Dalj (30km)
Section 4 : Dalj - Borovo selo - Borovo - Vukovar (19km)
Section 5 : Vukovar - Sotin - Opatovac (17km)
Section 6 : Opatovac - Šarengrad - Ilok (17km)
There is a huge complex of 15 pools in Bizovačke Toplice spa, there are pools with hot thermal water, as well as "normal" pools. There are also slides and all that fun stuff for kids. The largest pool is big olympic pool and it's not crowded so you can swim freely!