All in all it is solid. Nice graphics, and nice sound effects. I had fund playing it. I am missing some kind of hook to continue playing, some story behind, some real objective to keep me playing. I also missed some effects to make the experience more satisfying. I have recorded my play session in Playcocola, please check here:
Viewing post in MonsterBattle Cards jam comments
First of all, thank you for the really detailed review of my game (You're the only one, as far as I've seen, who has recorded his review).
A story is already planned but I wasn't be able to implement this in the 5 days of the jam(My list of wanted was way longer than the time I had). To build a objective for the player I have the following ideas: Give the player rewards (or some special events if he survives X rounds, some kind of achievement system or a public leaderboard.
If you have other suggestions, feel free to share them by leaving a comment. All suggestions will be used for further development of the game.