You’re right—adding enemy variety would greatly improve the gameplay experience. However, given my current situation, I’m not able to add more content because I can’t concentrate. In fact, if you look closely, you’ll notice that both the soldier and the spider are exactly the same, just with different sprites.
For the game, I had planned to let players choose the number of enemies and soldiers, decide whether they wanted to be on the enemy or allied side, and have multiple unit types within each faction with different stats. When you die with one character, you would simply switch to another one in the battle. The team that reaches the target score first wins.